diff --git a/ChangeLog b/ChangeLog
index f19cb05c..e0e038c5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+13-JUN-2018: 8.7.9
+
+- Fixes possible NPE
+
 13-JUN-2018: 8.7.8
 
 - Fixes scroll wheel zoom while panning
diff --git a/VERSION b/VERSION
index 250a6cda..697233a0 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.7.8
\ No newline at end of file
+8.7.9
\ No newline at end of file
diff --git a/src/main/webapp/cache.manifest b/src/main/webapp/cache.manifest
index fe51f0ef..21447549 100644
--- a/src/main/webapp/cache.manifest
+++ b/src/main/webapp/cache.manifest
@@ -1,7 +1,7 @@
 CACHE MANIFEST
 
 # THIS FILE WAS GENERATED. DO NOT MODIFY!
-# 06/13/2018 02:30 PM
+# 06/13/2018 03:15 PM
 
 app.html
 index.html?offline=1
diff --git a/src/main/webapp/js/app.min.js b/src/main/webapp/js/app.min.js
index 80fe79fc..fe455bec 100644
--- a/src/main/webapp/js/app.min.js
+++ b/src/main/webapp/js/app.min.js
@@ -2543,7 +2543,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),l);return m};Gr
 c)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var b=null;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){var c=document.createRange();c.selectNode(a);b.removeAllRanges();b.addRange(c)}}else(b=document.selection)&&"Control"!=b.type&&(a=b.createRange(),a.collapse(!0),c=b.createRange(),c.setEndPoint("StartToStart",a),c.select())};Graph.prototype.insertRow=function(a,b){for(var c=a.tBodies[0],d=0<c.rows.length?c.rows[0].cells.length:1,c=c.insertRow(b),
 e=0;e<d;e++)mxUtils.br(c.insertCell(-1));return c.cells[0]};Graph.prototype.deleteRow=function(a,b){a.tBodies[0].deleteRow(b)};Graph.prototype.insertColumn=function(a,b){var c=a.tHead;if(null!=c)for(var d=0;d<c.rows.length;d++){var e=document.createElement("th");c.rows[d].appendChild(e);mxUtils.br(e)}c=a.tBodies[0];for(d=0;d<c.rows.length;d++)e=c.rows[d].insertCell(b),mxUtils.br(e);return c.rows[0].cells[0<=b?b:c.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,b){if(0<=b)for(var c=
 a.tBodies[0].rows,d=0;d<c.length;d++)c[d].cells.length>b&&c[d].deleteCell(b)};Graph.prototype.pasteHtmlAtCaret=function(a){var b;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){b=b.getRangeAt(0);b.deleteContents();var c=document.createElement("div");c.innerHTML=a;a=document.createDocumentFragment();for(var d;d=c.firstChild;)lastNode=a.appendChild(d);b.insertNode(a)}}else(b=document.selection)&&"Control"!=b.type&&b.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 b){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(b){b=a.apply(this,arguments);if(mxEvent.isTouchEvent(b.getEvent())&&null==b.getState()){var c=this.getCellAt(b.graphX,b.graphY);null!=c&&this.isSwimlane(c)&&this.hitsSwimlaneContent(c,b.graphX,b.graphY)||(b.state=this.view.getState(c),null!=b.state&&null!=b.state.shape&&(this.container.style.cursor=b.state.shape.node.style.cursor))}null==b.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return b};var b=!1,c=!1,d=!1,e=this.fireMouseEvent;this.fireMouseEvent=function(a,f,g){a==mxEvent.MOUSE_DOWN&&(f=this.updateMouseEvent(f),b=this.isCellSelected(f.getCell()),c=this.isSelectionEmpty(),d=this.popupMenuHandler.isMenuShowing());e.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,e){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==e.getState()||!e.isSource(e.getState().control))&&(this.popupMenuHandler.popupTrigger||!d&&!mxEvent.isMouseEvent(e.getEvent())&&
 (c&&null==e.getCell()&&this.isSelectionEmpty()||b&&this.isCellSelected(e.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var b=[],c=0,d=a.rangeCount;c<d;++c)b.push(a.getRangeAt(c));return b}}else if(document.selection&&
@@ -7186,7 +7186,7 @@ var U=document.createElement("input");U.style.cssText="margin:0 8px 0 8px;";U.se
 v.className="geBtn",e.appendChild(v));PrintDialog.previewEnabled&&(v=mxUtils.button(mxResources.get("preview"),function(){a.hideDialog();d(!1)}),v.className="geBtn",e.appendChild(v));v=mxUtils.button(mxResources.get(PrintDialog.previewEnabled?"print":"ok"),function(){a.hideDialog();d(!0)});v.className="geBtn gePrimaryBtn";e.appendChild(v);a.editor.cancelFirst||e.appendChild(h);k.appendChild(e);this.container=k};var v=ChangePageSetup.prototype.execute;ChangePageSetup.prototype.execute=function(){null==
 this.page&&(this.page=this.ui.currentPage);this.page!=this.ui.currentPage?null!=this.page.viewState&&(this.ignoreColor||(this.page.viewState.background=this.color),this.ignoreImage||(this.page.viewState.backgroundImage=this.image),null!=this.format&&(this.page.viewState.pageFormat=this.format),null!=this.mathEnabled&&(this.page.viewState.mathEnabled=this.mathEnabled),null!=this.shadowVisible&&(this.page.viewState.shadowVisible=this.shadowVisible)):(v.apply(this,arguments),null!=this.mathEnabled&&
 this.mathEnabled!=this.ui.isMathEnabled()&&(this.ui.setMathEnabled(this.mathEnabled),this.mathEnabled=!this.mathEnabled),null!=this.shadowVisible&&this.shadowVisible!=this.ui.editor.graph.shadowVisible&&(this.ui.editor.graph.setShadowVisible(this.shadowVisible),this.shadowVisible=!this.shadowVisible))}})();
-(function(){var a=new mxObjectCodec(new ChangePageSetup,["ui","previousColor","previousImage","previousFormat"]);a.beforeDecode=function(a,c,d){d.ui=a.ui;return c};a.afterDecode=function(a,c,d){d.previousColor=d.color;d.previousImage=d.image;d.previousFormat=d.format;null!=d.foldingEnabled&&(d.foldingEnabled=!d.foldingEnabled);null!=d.mathEnabled&&(d.mathEnabled=!d.mathEnabled);null!=d.shadowVisible&&(d.shadowVisible=!d.shadowVisible);return d};mxCodecRegistry.register(a)})();(function(){EditorUi.VERSION="8.7.8";EditorUi.compactUi="atlas"!=uiTheme;EditorUi.enableLogging=/.*\.draw\.io$/.test(window.location.hostname)&&"support.draw.io"!=window.location.hostname;EditorUi.enablePlantUml=EditorUi.enableLogging;EditorUi.isElectronApp=null!=window&&null!=window.process&&null!=window.process.versions&&null!=window.process.versions.electron;EditorUi.scratchpadHelpLink="https://desk.draw.io/support/solutions/articles/16000042367";EditorUi.prototype.emptyDiagramXml='<mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel>';
+(function(){var a=new mxObjectCodec(new ChangePageSetup,["ui","previousColor","previousImage","previousFormat"]);a.beforeDecode=function(a,c,d){d.ui=a.ui;return c};a.afterDecode=function(a,c,d){d.previousColor=d.color;d.previousImage=d.image;d.previousFormat=d.format;null!=d.foldingEnabled&&(d.foldingEnabled=!d.foldingEnabled);null!=d.mathEnabled&&(d.mathEnabled=!d.mathEnabled);null!=d.shadowVisible&&(d.shadowVisible=!d.shadowVisible);return d};mxCodecRegistry.register(a)})();(function(){EditorUi.VERSION="8.7.9";EditorUi.compactUi="atlas"!=uiTheme;EditorUi.enableLogging=/.*\.draw\.io$/.test(window.location.hostname)&&"support.draw.io"!=window.location.hostname;EditorUi.enablePlantUml=EditorUi.enableLogging;EditorUi.isElectronApp=null!=window&&null!=window.process&&null!=window.process.versions&&null!=window.process.versions.electron;EditorUi.scratchpadHelpLink="https://desk.draw.io/support/solutions/articles/16000042367";EditorUi.prototype.emptyDiagramXml='<mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel>';
 EditorUi.prototype.emptyLibraryXml="<mxlibrary>[]</mxlibrary>";EditorUi.prototype.mode=null;EditorUi.prototype.sidebarFooterHeight=36;EditorUi.prototype.defaultCustomShapeStyle="shape=stencil(tZRtTsQgEEBPw1+DJR7AoN6DbWftpAgE0Ortd/jYRGq72R+YNE2YgTePloEJGWblgA18ZuKFDcMj5/Sm8boZq+BgjCX4pTyqk6ZlKROitwusOMXKQDODx5iy4pXxZ5qTHiFHawxB0JrQZH7lCabQ0Fr+XWC1/E8zcsT/gAi+Subo2/3Mh6d/oJb5nU1b5tW7r2knautaa3T+U32o7f7vZwpJkaNDLORJjcu7t59m2jXxqX9un+tt022acsfmoKaQZ+vhhswZtS6Ne/ThQGt0IV0N3Yyv6P3CeT9/tHO0XFI5cAE=);whiteSpace=wrap;html=1;";
 EditorUi.prototype.svgBrokenImage=Graph.createSvgImage(10,10,'<rect x="0" y="0" width="10" height="10" stroke="#000" fill="transparent"/><path d="m 0 0 L 10 10 L 0 10 L 10 0" stroke="#000" fill="transparent"/>');EditorUi.prototype.crossOriginImages=!mxClient.IS_IE;EditorUi.prototype.maxBackgroundSize=1600;EditorUi.prototype.maxImageSize=520;EditorUi.prototype.resampleThreshold=1E5;EditorUi.prototype.maxImageBytes=1E6;EditorUi.prototype.maxBackgroundBytes=25E5;EditorUi.prototype.currentFile=null;EditorUi.prototype.printPdfExport=
 !1;EditorUi.prototype.pdfPageExport=!0;EditorUi.prototype.formatEnabled="0"!=urlParams.format;EditorUi.prototype.closableScratchpad=!0;(function(){EditorUi.prototype.useCanvasForExport=!1;EditorUi.prototype.jpgSupported=!1;try{var a=document.createElement("canvas");EditorUi.prototype.canvasSupported=!(!a.getContext||!a.getContext("2d"))}catch(u){}try{var b=document.createElement("canvas"),c=new Image;c.onload=function(){try{b.getContext("2d").drawImage(c,0,0);var a=b.toDataURL("image/png");EditorUi.prototype.useCanvasForExport=
diff --git a/src/main/webapp/js/atlas-viewer.min.js b/src/main/webapp/js/atlas-viewer.min.js
index c736f98c..f4547aed 100644
--- a/src/main/webapp/js/atlas-viewer.min.js
+++ b/src/main/webapp/js/atlas-viewer.min.js
@@ -2351,7 +2351,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),p);return m};Gr
 b)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var d=null;if(window.getSelection){if(d=window.getSelection(),d.getRangeAt&&d.rangeCount){var b=document.createRange();b.selectNode(a);d.removeAllRanges();d.addRange(b)}}else(d=document.selection)&&"Control"!=d.type&&(a=d.createRange(),a.collapse(!0),b=d.createRange(),b.setEndPoint("StartToStart",a),b.select())};Graph.prototype.insertRow=function(a,d){for(var b=a.tBodies[0],c=0<b.rows.length?b.rows[0].cells.length:1,b=b.insertRow(d),
 f=0;f<c;f++)mxUtils.br(b.insertCell(-1));return b.cells[0]};Graph.prototype.deleteRow=function(a,d){a.tBodies[0].deleteRow(d)};Graph.prototype.insertColumn=function(a,d){var b=a.tHead;if(null!=b)for(var c=0;c<b.rows.length;c++){var f=document.createElement("th");b.rows[c].appendChild(f);mxUtils.br(f)}b=a.tBodies[0];for(c=0;c<b.rows.length;c++)f=b.rows[c].insertCell(d),mxUtils.br(f);return b.rows[0].cells[0<=d?d:b.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,d){if(0<=d)for(var b=
 a.tBodies[0].rows,c=0;c<b.length;c++)b[c].cells.length>d&&b[c].deleteCell(d)};Graph.prototype.pasteHtmlAtCaret=function(a){var d;if(window.getSelection){if(d=window.getSelection(),d.getRangeAt&&d.rangeCount){d=d.getRangeAt(0);d.deleteContents();var b=document.createElement("div");b.innerHTML=a;a=document.createDocumentFragment();for(var c;c=b.firstChild;)lastNode=a.appendChild(c);d.insertNode(a)}}else(d=document.selection)&&"Control"!=d.type&&d.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,d){d=null!=d?d:a;var b=document.createElement("a");b.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||b.setAttribute("title",a);null!=this.linkTarget&&b.setAttribute("target",this.linkTarget);40<d.length&&(d=d.substring(0,26)+"..."+d.substring(d.length-10));mxUtils.write(b,d);return b};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,d){d=null!=d?d:a;var b=document.createElement("a");b.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||b.setAttribute("title",a);null!=this.linkTarget&&b.setAttribute("target",this.linkTarget);40<d.length&&(d=d.substring(0,26)+"..."+d.substring(d.length-10));mxUtils.write(b,d);return b};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 d){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(d){d=a.apply(this,arguments);if(mxEvent.isTouchEvent(d.getEvent())&&null==d.getState()){var b=this.getCellAt(d.graphX,d.graphY);null!=b&&this.isSwimlane(b)&&this.hitsSwimlaneContent(b,d.graphX,d.graphY)||(d.state=this.view.getState(b),null!=d.state&&null!=d.state.shape&&(this.container.style.cursor=d.state.shape.node.style.cursor))}null==d.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return d};var d=!1,b=!1,c=!1,f=this.fireMouseEvent;this.fireMouseEvent=function(a,e,g){a==mxEvent.MOUSE_DOWN&&(e=this.updateMouseEvent(e),d=this.isCellSelected(e.getCell()),b=this.isSelectionEmpty(),c=this.popupMenuHandler.isMenuShowing());f.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,f){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==f.getState()||!f.isSource(f.getState().control))&&(this.popupMenuHandler.popupTrigger||!c&&!mxEvent.isMouseEvent(f.getEvent())&&
 (b&&null==f.getCell()&&this.isSelectionEmpty()||d&&this.isCellSelected(f.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var d=[],b=0,c=a.rangeCount;b<c;++b)d.push(a.getRangeAt(b));return d}}else if(document.selection&&
diff --git a/src/main/webapp/js/atlas.min.js b/src/main/webapp/js/atlas.min.js
index bcaa4d8f..04a06451 100644
--- a/src/main/webapp/js/atlas.min.js
+++ b/src/main/webapp/js/atlas.min.js
@@ -2543,7 +2543,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),l);return m};Gr
 c)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var b=null;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){var c=document.createRange();c.selectNode(a);b.removeAllRanges();b.addRange(c)}}else(b=document.selection)&&"Control"!=b.type&&(a=b.createRange(),a.collapse(!0),c=b.createRange(),c.setEndPoint("StartToStart",a),c.select())};Graph.prototype.insertRow=function(a,b){for(var c=a.tBodies[0],d=0<c.rows.length?c.rows[0].cells.length:1,c=c.insertRow(b),
 e=0;e<d;e++)mxUtils.br(c.insertCell(-1));return c.cells[0]};Graph.prototype.deleteRow=function(a,b){a.tBodies[0].deleteRow(b)};Graph.prototype.insertColumn=function(a,b){var c=a.tHead;if(null!=c)for(var d=0;d<c.rows.length;d++){var e=document.createElement("th");c.rows[d].appendChild(e);mxUtils.br(e)}c=a.tBodies[0];for(d=0;d<c.rows.length;d++)e=c.rows[d].insertCell(b),mxUtils.br(e);return c.rows[0].cells[0<=b?b:c.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,b){if(0<=b)for(var c=
 a.tBodies[0].rows,d=0;d<c.length;d++)c[d].cells.length>b&&c[d].deleteCell(b)};Graph.prototype.pasteHtmlAtCaret=function(a){var b;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){b=b.getRangeAt(0);b.deleteContents();var c=document.createElement("div");c.innerHTML=a;a=document.createDocumentFragment();for(var d;d=c.firstChild;)lastNode=a.appendChild(d);b.insertNode(a)}}else(b=document.selection)&&"Control"!=b.type&&b.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 b){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(b){b=a.apply(this,arguments);if(mxEvent.isTouchEvent(b.getEvent())&&null==b.getState()){var c=this.getCellAt(b.graphX,b.graphY);null!=c&&this.isSwimlane(c)&&this.hitsSwimlaneContent(c,b.graphX,b.graphY)||(b.state=this.view.getState(c),null!=b.state&&null!=b.state.shape&&(this.container.style.cursor=b.state.shape.node.style.cursor))}null==b.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return b};var b=!1,c=!1,d=!1,e=this.fireMouseEvent;this.fireMouseEvent=function(a,f,g){a==mxEvent.MOUSE_DOWN&&(f=this.updateMouseEvent(f),b=this.isCellSelected(f.getCell()),c=this.isSelectionEmpty(),d=this.popupMenuHandler.isMenuShowing());e.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,e){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==e.getState()||!e.isSource(e.getState().control))&&(this.popupMenuHandler.popupTrigger||!d&&!mxEvent.isMouseEvent(e.getEvent())&&
 (c&&null==e.getCell()&&this.isSelectionEmpty()||b&&this.isCellSelected(e.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var b=[],c=0,d=a.rangeCount;c<d;++c)b.push(a.getRangeAt(c));return b}}else if(document.selection&&
@@ -7186,7 +7186,7 @@ var U=document.createElement("input");U.style.cssText="margin:0 8px 0 8px;";U.se
 m.className="geBtn",f.appendChild(m));PrintDialog.previewEnabled&&(m=mxUtils.button(mxResources.get("preview"),function(){b.hideDialog();c(!1)}),m.className="geBtn",f.appendChild(m));m=mxUtils.button(mxResources.get(PrintDialog.previewEnabled?"print":"ok"),function(){b.hideDialog();c(!0)});m.className="geBtn gePrimaryBtn";f.appendChild(m);b.editor.cancelFirst||f.appendChild(q);d.appendChild(f);this.container=d};var w=ChangePageSetup.prototype.execute;ChangePageSetup.prototype.execute=function(){null==
 this.page&&(this.page=this.ui.currentPage);this.page!=this.ui.currentPage?null!=this.page.viewState&&(this.ignoreColor||(this.page.viewState.background=this.color),this.ignoreImage||(this.page.viewState.backgroundImage=this.image),null!=this.format&&(this.page.viewState.pageFormat=this.format),null!=this.mathEnabled&&(this.page.viewState.mathEnabled=this.mathEnabled),null!=this.shadowVisible&&(this.page.viewState.shadowVisible=this.shadowVisible)):(w.apply(this,arguments),null!=this.mathEnabled&&
 this.mathEnabled!=this.ui.isMathEnabled()&&(this.ui.setMathEnabled(this.mathEnabled),this.mathEnabled=!this.mathEnabled),null!=this.shadowVisible&&this.shadowVisible!=this.ui.editor.graph.shadowVisible&&(this.ui.editor.graph.setShadowVisible(this.shadowVisible),this.shadowVisible=!this.shadowVisible))}})();
-(function(){var a=new mxObjectCodec(new ChangePageSetup,["ui","previousColor","previousImage","previousFormat"]);a.beforeDecode=function(a,d,c){c.ui=a.ui;return d};a.afterDecode=function(a,d,c){c.previousColor=c.color;c.previousImage=c.image;c.previousFormat=c.format;null!=c.foldingEnabled&&(c.foldingEnabled=!c.foldingEnabled);null!=c.mathEnabled&&(c.mathEnabled=!c.mathEnabled);null!=c.shadowVisible&&(c.shadowVisible=!c.shadowVisible);return c};mxCodecRegistry.register(a)})();(function(){EditorUi.VERSION="8.7.8";EditorUi.compactUi="atlas"!=uiTheme;EditorUi.enableLogging=/.*\.draw\.io$/.test(window.location.hostname)&&"support.draw.io"!=window.location.hostname;EditorUi.enablePlantUml=EditorUi.enableLogging;EditorUi.isElectronApp=null!=window&&null!=window.process&&null!=window.process.versions&&null!=window.process.versions.electron;EditorUi.scratchpadHelpLink="https://desk.draw.io/support/solutions/articles/16000042367";EditorUi.prototype.emptyDiagramXml='<mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel>';
+(function(){var a=new mxObjectCodec(new ChangePageSetup,["ui","previousColor","previousImage","previousFormat"]);a.beforeDecode=function(a,d,c){c.ui=a.ui;return d};a.afterDecode=function(a,d,c){c.previousColor=c.color;c.previousImage=c.image;c.previousFormat=c.format;null!=c.foldingEnabled&&(c.foldingEnabled=!c.foldingEnabled);null!=c.mathEnabled&&(c.mathEnabled=!c.mathEnabled);null!=c.shadowVisible&&(c.shadowVisible=!c.shadowVisible);return c};mxCodecRegistry.register(a)})();(function(){EditorUi.VERSION="8.7.9";EditorUi.compactUi="atlas"!=uiTheme;EditorUi.enableLogging=/.*\.draw\.io$/.test(window.location.hostname)&&"support.draw.io"!=window.location.hostname;EditorUi.enablePlantUml=EditorUi.enableLogging;EditorUi.isElectronApp=null!=window&&null!=window.process&&null!=window.process.versions&&null!=window.process.versions.electron;EditorUi.scratchpadHelpLink="https://desk.draw.io/support/solutions/articles/16000042367";EditorUi.prototype.emptyDiagramXml='<mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel>';
 EditorUi.prototype.emptyLibraryXml="<mxlibrary>[]</mxlibrary>";EditorUi.prototype.mode=null;EditorUi.prototype.sidebarFooterHeight=36;EditorUi.prototype.defaultCustomShapeStyle="shape=stencil(tZRtTsQgEEBPw1+DJR7AoN6DbWftpAgE0Ortd/jYRGq72R+YNE2YgTePloEJGWblgA18ZuKFDcMj5/Sm8boZq+BgjCX4pTyqk6ZlKROitwusOMXKQDODx5iy4pXxZ5qTHiFHawxB0JrQZH7lCabQ0Fr+XWC1/E8zcsT/gAi+Subo2/3Mh6d/oJb5nU1b5tW7r2knautaa3T+U32o7f7vZwpJkaNDLORJjcu7t59m2jXxqX9un+tt022acsfmoKaQZ+vhhswZtS6Ne/ThQGt0IV0N3Yyv6P3CeT9/tHO0XFI5cAE=);whiteSpace=wrap;html=1;";
 EditorUi.prototype.svgBrokenImage=Graph.createSvgImage(10,10,'<rect x="0" y="0" width="10" height="10" stroke="#000" fill="transparent"/><path d="m 0 0 L 10 10 L 0 10 L 10 0" stroke="#000" fill="transparent"/>');EditorUi.prototype.crossOriginImages=!mxClient.IS_IE;EditorUi.prototype.maxBackgroundSize=1600;EditorUi.prototype.maxImageSize=520;EditorUi.prototype.resampleThreshold=1E5;EditorUi.prototype.maxImageBytes=1E6;EditorUi.prototype.maxBackgroundBytes=25E5;EditorUi.prototype.currentFile=null;EditorUi.prototype.printPdfExport=
 !1;EditorUi.prototype.pdfPageExport=!0;EditorUi.prototype.formatEnabled="0"!=urlParams.format;EditorUi.prototype.closableScratchpad=!0;(function(){EditorUi.prototype.useCanvasForExport=!1;EditorUi.prototype.jpgSupported=!1;try{var b=document.createElement("canvas");EditorUi.prototype.canvasSupported=!(!b.getContext||!b.getContext("2d"))}catch(q){}try{var a=document.createElement("canvas"),c=new Image;c.onload=function(){try{a.getContext("2d").drawImage(c,0,0);var b=a.toDataURL("image/png");EditorUi.prototype.useCanvasForExport=
diff --git a/src/main/webapp/js/embed-static.min.js b/src/main/webapp/js/embed-static.min.js
index ec9c7874..d86fc181 100644
--- a/src/main/webapp/js/embed-static.min.js
+++ b/src/main/webapp/js/embed-static.min.js
@@ -184,7 +184,7 @@ f)+"\n"+t+"}":"{"+z.join(",")+"}";f=t;return l}}"function"!==typeof Date.prototy
 e=/[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,f,g,h={"\b":"\\b","\t":"\\t","\n":"\\n","\f":"\\f","\r":"\\r",'"':'\\"',"\\":"\\\\"},k;"function"!==typeof JSON.stringify&&(JSON.stringify=function(a,b,d){var e;g=f="";if("number"===typeof d)for(e=0;e<d;e+=1)g+=" ";else"string"===typeof d&&(g=d);if((k=b)&&"function"!==typeof b&&("object"!==typeof b||"number"!==typeof b.length))throw Error("JSON.stringify");return c("",{"":a})});
 "function"!==typeof JSON.parse&&(JSON.parse=function(a,b){function c(a,d){var e,f,g=a[d];if(g&&"object"===typeof g)for(e in g)Object.prototype.hasOwnProperty.call(g,e)&&(f=c(g,e),void 0!==f?g[e]=f:delete g[e]);return b.call(a,d,g)}var e;a=""+a;d.lastIndex=0;d.test(a)&&(a=a.replace(d,function(a){return"\\u"+("0000"+a.charCodeAt(0).toString(16)).slice(-4)}));if(/^[\],:{}\s]*$/.test(a.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,"@").replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
 "]").replace(/(?:^|:|,)(?:\s*\[)+/g,"")))return e=eval("("+a+")"),"function"===typeof b?c({"":e},""):e;throw new SyntaxError("JSON.parse");})})();"undefined"===typeof window.mxBasePath&&(window.mxBasePath="https://www.draw.io/mxgraph/");window.mxLoadStylesheets=window.mxLoadStylesheets||!1;window.mxLoadResources=window.mxLoadResources||!1;window.mxLanguage=window.mxLanguage||"en";window.urlParams=window.urlParams||{};window.MAX_REQUEST_SIZE=window.MAX_REQUEST_SIZE||10485760;window.MAX_AREA=window.MAX_AREA||225E6;window.EXPORT_URL=window.EXPORT_URL||"/export";window.SAVE_URL=window.SAVE_URL||"/save";window.OPEN_URL=window.OPEN_URL||"/open";window.RESOURCES_PATH=window.RESOURCES_PATH||"resources";window.RESOURCE_BASE=window.RESOURCE_BASE||window.RESOURCES_PATH+"/grapheditor";window.STENCIL_PATH=window.STENCIL_PATH||"stencils";window.IMAGE_PATH=window.IMAGE_PATH||"images";
-window.STYLE_PATH=window.STYLE_PATH||"styles";window.CSS_PATH=window.CSS_PATH||"styles";window.OPEN_FORM=window.OPEN_FORM||"open.html";window.mxBasePath=window.mxBasePath||"../../../src";window.mxLanguage=window.mxLanguage||urlParams.lang;window.mxLanguages=window.mxLanguages||["de"];var mxClient={VERSION:"8.7.8",IS_IE:0<=navigator.userAgent.indexOf("MSIE"),IS_IE6:0<=navigator.userAgent.indexOf("MSIE 6"),IS_IE11:!!navigator.userAgent.match(/Trident\/7\./),IS_EDGE:!!navigator.userAgent.match(/Edge\//),IS_QUIRKS:0<=navigator.userAgent.indexOf("MSIE")&&(null==document.documentMode||5==document.documentMode),IS_EM:"spellcheck"in document.createElement("textarea")&&8==document.documentMode,VML_PREFIX:"v",OFFICE_PREFIX:"o",IS_NS:0<=navigator.userAgent.indexOf("Mozilla/")&&0>navigator.userAgent.indexOf("MSIE")&&
+window.STYLE_PATH=window.STYLE_PATH||"styles";window.CSS_PATH=window.CSS_PATH||"styles";window.OPEN_FORM=window.OPEN_FORM||"open.html";window.mxBasePath=window.mxBasePath||"../../../src";window.mxLanguage=window.mxLanguage||urlParams.lang;window.mxLanguages=window.mxLanguages||["de"];var mxClient={VERSION:"8.7.9",IS_IE:0<=navigator.userAgent.indexOf("MSIE"),IS_IE6:0<=navigator.userAgent.indexOf("MSIE 6"),IS_IE11:!!navigator.userAgent.match(/Trident\/7\./),IS_EDGE:!!navigator.userAgent.match(/Edge\//),IS_QUIRKS:0<=navigator.userAgent.indexOf("MSIE")&&(null==document.documentMode||5==document.documentMode),IS_EM:"spellcheck"in document.createElement("textarea")&&8==document.documentMode,VML_PREFIX:"v",OFFICE_PREFIX:"o",IS_NS:0<=navigator.userAgent.indexOf("Mozilla/")&&0>navigator.userAgent.indexOf("MSIE")&&
 0>navigator.userAgent.indexOf("Edge/"),IS_OP:0<=navigator.userAgent.indexOf("Opera/")||0<=navigator.userAgent.indexOf("OPR/"),IS_OT:0<=navigator.userAgent.indexOf("Presto/")&&0>navigator.userAgent.indexOf("Presto/2.4.")&&0>navigator.userAgent.indexOf("Presto/2.3.")&&0>navigator.userAgent.indexOf("Presto/2.2.")&&0>navigator.userAgent.indexOf("Presto/2.1.")&&0>navigator.userAgent.indexOf("Presto/2.0.")&&0>navigator.userAgent.indexOf("Presto/1."),IS_SF:0<=navigator.userAgent.indexOf("AppleWebKit/")&&
 0>navigator.userAgent.indexOf("Chrome/")&&0>navigator.userAgent.indexOf("Edge/"),IS_IOS:navigator.userAgent.match(/(iPad|iPhone|iPod)/g)?!0:!1,IS_GC:0<=navigator.userAgent.indexOf("Chrome/")&&0>navigator.userAgent.indexOf("Edge/"),IS_CHROMEAPP:null!=window.chrome&&null!=chrome.app&&null!=chrome.app.runtime,IS_FF:0<=navigator.userAgent.indexOf("Firefox/"),IS_MT:0<=navigator.userAgent.indexOf("Firefox/")&&0>navigator.userAgent.indexOf("Firefox/1.")&&0>navigator.userAgent.indexOf("Firefox/2.")||0<=navigator.userAgent.indexOf("Iceweasel/")&&
 0>navigator.userAgent.indexOf("Iceweasel/1.")&&0>navigator.userAgent.indexOf("Iceweasel/2.")||0<=navigator.userAgent.indexOf("SeaMonkey/")&&0>navigator.userAgent.indexOf("SeaMonkey/1.")||0<=navigator.userAgent.indexOf("Iceape/")&&0>navigator.userAgent.indexOf("Iceape/1."),IS_SVG:0<=navigator.userAgent.indexOf("Firefox/")||0<=navigator.userAgent.indexOf("Iceweasel/")||0<=navigator.userAgent.indexOf("Seamonkey/")||0<=navigator.userAgent.indexOf("Iceape/")||0<=navigator.userAgent.indexOf("Galeon/")||
@@ -1697,7 +1697,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),l);return m};Gr
 c)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var b=null;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){var c=document.createRange();c.selectNode(a);b.removeAllRanges();b.addRange(c)}}else(b=document.selection)&&"Control"!=b.type&&(a=b.createRange(),a.collapse(!0),c=b.createRange(),c.setEndPoint("StartToStart",a),c.select())};Graph.prototype.insertRow=function(a,b){for(var c=a.tBodies[0],d=0<c.rows.length?c.rows[0].cells.length:1,c=c.insertRow(b),
 e=0;e<d;e++)mxUtils.br(c.insertCell(-1));return c.cells[0]};Graph.prototype.deleteRow=function(a,b){a.tBodies[0].deleteRow(b)};Graph.prototype.insertColumn=function(a,b){var c=a.tHead;if(null!=c)for(var d=0;d<c.rows.length;d++){var e=document.createElement("th");c.rows[d].appendChild(e);mxUtils.br(e)}c=a.tBodies[0];for(d=0;d<c.rows.length;d++)e=c.rows[d].insertCell(b),mxUtils.br(e);return c.rows[0].cells[0<=b?b:c.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,b){if(0<=b)for(var c=
 a.tBodies[0].rows,d=0;d<c.length;d++)c[d].cells.length>b&&c[d].deleteCell(b)};Graph.prototype.pasteHtmlAtCaret=function(a){var b;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){b=b.getRangeAt(0);b.deleteContents();var c=document.createElement("div");c.innerHTML=a;a=document.createDocumentFragment();for(var d;d=c.firstChild;)lastNode=a.appendChild(d);b.insertNode(a)}}else(b=document.selection)&&"Control"!=b.type&&b.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 b){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(b){b=a.apply(this,arguments);if(mxEvent.isTouchEvent(b.getEvent())&&null==b.getState()){var c=this.getCellAt(b.graphX,b.graphY);null!=c&&this.isSwimlane(c)&&this.hitsSwimlaneContent(c,b.graphX,b.graphY)||(b.state=this.view.getState(c),null!=b.state&&null!=b.state.shape&&(this.container.style.cursor=b.state.shape.node.style.cursor))}null==b.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return b};var b=!1,c=!1,d=!1,e=this.fireMouseEvent;this.fireMouseEvent=function(a,f,g){a==mxEvent.MOUSE_DOWN&&(f=this.updateMouseEvent(f),b=this.isCellSelected(f.getCell()),c=this.isSelectionEmpty(),d=this.popupMenuHandler.isMenuShowing());e.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,e){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==e.getState()||!e.isSource(e.getState().control))&&(this.popupMenuHandler.popupTrigger||!d&&!mxEvent.isMouseEvent(e.getEvent())&&
 (c&&null==e.getCell()&&this.isSelectionEmpty()||b&&this.isCellSelected(e.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var b=[],c=0,d=a.rangeCount;c<d;++c)b.push(a.getRangeAt(c));return b}}else if(document.selection&&
diff --git a/src/main/webapp/js/mxgraph/Graph.js b/src/main/webapp/js/mxgraph/Graph.js
index 45affdf1..3442bd09 100644
--- a/src/main/webapp/js/mxgraph/Graph.js
+++ b/src/main/webapp/js/mxgraph/Graph.js
@@ -6170,7 +6170,7 @@ if (typeof mxVertexHandler != 'undefined')
 			var a = document.createElement('a');
 			a.setAttribute('href', this.getAbsoluteUrl(link));
 			
-			if (!this.isCustomLink(link))
+			if (link != null && !this.isCustomLink(link))
 			{
 				a.setAttribute('title', link);
 			}
diff --git a/src/main/webapp/js/reader.min.js b/src/main/webapp/js/reader.min.js
index 7291afe9..26318f57 100644
--- a/src/main/webapp/js/reader.min.js
+++ b/src/main/webapp/js/reader.min.js
@@ -184,7 +184,7 @@ f)+"\n"+t+"}":"{"+z.join(",")+"}";f=t;return l}}"function"!==typeof Date.prototy
 e=/[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,f,g,h={"\b":"\\b","\t":"\\t","\n":"\\n","\f":"\\f","\r":"\\r",'"':'\\"',"\\":"\\\\"},k;"function"!==typeof JSON.stringify&&(JSON.stringify=function(a,b,d){var e;g=f="";if("number"===typeof d)for(e=0;e<d;e+=1)g+=" ";else"string"===typeof d&&(g=d);if((k=b)&&"function"!==typeof b&&("object"!==typeof b||"number"!==typeof b.length))throw Error("JSON.stringify");return c("",{"":a})});
 "function"!==typeof JSON.parse&&(JSON.parse=function(a,b){function c(a,d){var e,f,g=a[d];if(g&&"object"===typeof g)for(e in g)Object.prototype.hasOwnProperty.call(g,e)&&(f=c(g,e),void 0!==f?g[e]=f:delete g[e]);return b.call(a,d,g)}var e;a=""+a;d.lastIndex=0;d.test(a)&&(a=a.replace(d,function(a){return"\\u"+("0000"+a.charCodeAt(0).toString(16)).slice(-4)}));if(/^[\],:{}\s]*$/.test(a.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,"@").replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
 "]").replace(/(?:^|:|,)(?:\s*\[)+/g,"")))return e=eval("("+a+")"),"function"===typeof b?c({"":e},""):e;throw new SyntaxError("JSON.parse");})})();"undefined"===typeof window.mxBasePath&&(window.mxBasePath="https://www.draw.io/mxgraph/");window.mxLoadStylesheets=window.mxLoadStylesheets||!1;window.mxLoadResources=window.mxLoadResources||!1;window.mxLanguage=window.mxLanguage||"en";window.urlParams=window.urlParams||{};window.MAX_REQUEST_SIZE=window.MAX_REQUEST_SIZE||10485760;window.MAX_AREA=window.MAX_AREA||225E6;window.EXPORT_URL=window.EXPORT_URL||"/export";window.SAVE_URL=window.SAVE_URL||"/save";window.OPEN_URL=window.OPEN_URL||"/open";window.RESOURCES_PATH=window.RESOURCES_PATH||"resources";window.RESOURCE_BASE=window.RESOURCE_BASE||window.RESOURCES_PATH+"/grapheditor";window.STENCIL_PATH=window.STENCIL_PATH||"stencils";window.IMAGE_PATH=window.IMAGE_PATH||"images";
-window.STYLE_PATH=window.STYLE_PATH||"styles";window.CSS_PATH=window.CSS_PATH||"styles";window.OPEN_FORM=window.OPEN_FORM||"open.html";window.mxBasePath=window.mxBasePath||"../../../src";window.mxLanguage=window.mxLanguage||urlParams.lang;window.mxLanguages=window.mxLanguages||["de"];var mxClient={VERSION:"8.7.8",IS_IE:0<=navigator.userAgent.indexOf("MSIE"),IS_IE6:0<=navigator.userAgent.indexOf("MSIE 6"),IS_IE11:!!navigator.userAgent.match(/Trident\/7\./),IS_EDGE:!!navigator.userAgent.match(/Edge\//),IS_QUIRKS:0<=navigator.userAgent.indexOf("MSIE")&&(null==document.documentMode||5==document.documentMode),IS_EM:"spellcheck"in document.createElement("textarea")&&8==document.documentMode,VML_PREFIX:"v",OFFICE_PREFIX:"o",IS_NS:0<=navigator.userAgent.indexOf("Mozilla/")&&0>navigator.userAgent.indexOf("MSIE")&&
+window.STYLE_PATH=window.STYLE_PATH||"styles";window.CSS_PATH=window.CSS_PATH||"styles";window.OPEN_FORM=window.OPEN_FORM||"open.html";window.mxBasePath=window.mxBasePath||"../../../src";window.mxLanguage=window.mxLanguage||urlParams.lang;window.mxLanguages=window.mxLanguages||["de"];var mxClient={VERSION:"8.7.9",IS_IE:0<=navigator.userAgent.indexOf("MSIE"),IS_IE6:0<=navigator.userAgent.indexOf("MSIE 6"),IS_IE11:!!navigator.userAgent.match(/Trident\/7\./),IS_EDGE:!!navigator.userAgent.match(/Edge\//),IS_QUIRKS:0<=navigator.userAgent.indexOf("MSIE")&&(null==document.documentMode||5==document.documentMode),IS_EM:"spellcheck"in document.createElement("textarea")&&8==document.documentMode,VML_PREFIX:"v",OFFICE_PREFIX:"o",IS_NS:0<=navigator.userAgent.indexOf("Mozilla/")&&0>navigator.userAgent.indexOf("MSIE")&&
 0>navigator.userAgent.indexOf("Edge/"),IS_OP:0<=navigator.userAgent.indexOf("Opera/")||0<=navigator.userAgent.indexOf("OPR/"),IS_OT:0<=navigator.userAgent.indexOf("Presto/")&&0>navigator.userAgent.indexOf("Presto/2.4.")&&0>navigator.userAgent.indexOf("Presto/2.3.")&&0>navigator.userAgent.indexOf("Presto/2.2.")&&0>navigator.userAgent.indexOf("Presto/2.1.")&&0>navigator.userAgent.indexOf("Presto/2.0.")&&0>navigator.userAgent.indexOf("Presto/1."),IS_SF:0<=navigator.userAgent.indexOf("AppleWebKit/")&&
 0>navigator.userAgent.indexOf("Chrome/")&&0>navigator.userAgent.indexOf("Edge/"),IS_IOS:navigator.userAgent.match(/(iPad|iPhone|iPod)/g)?!0:!1,IS_GC:0<=navigator.userAgent.indexOf("Chrome/")&&0>navigator.userAgent.indexOf("Edge/"),IS_CHROMEAPP:null!=window.chrome&&null!=chrome.app&&null!=chrome.app.runtime,IS_FF:0<=navigator.userAgent.indexOf("Firefox/"),IS_MT:0<=navigator.userAgent.indexOf("Firefox/")&&0>navigator.userAgent.indexOf("Firefox/1.")&&0>navigator.userAgent.indexOf("Firefox/2.")||0<=navigator.userAgent.indexOf("Iceweasel/")&&
 0>navigator.userAgent.indexOf("Iceweasel/1.")&&0>navigator.userAgent.indexOf("Iceweasel/2.")||0<=navigator.userAgent.indexOf("SeaMonkey/")&&0>navigator.userAgent.indexOf("SeaMonkey/1.")||0<=navigator.userAgent.indexOf("Iceape/")&&0>navigator.userAgent.indexOf("Iceape/1."),IS_SVG:0<=navigator.userAgent.indexOf("Firefox/")||0<=navigator.userAgent.indexOf("Iceweasel/")||0<=navigator.userAgent.indexOf("Seamonkey/")||0<=navigator.userAgent.indexOf("Iceape/")||0<=navigator.userAgent.indexOf("Galeon/")||
@@ -1697,7 +1697,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),l);return m};Gr
 c)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var b=null;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){var c=document.createRange();c.selectNode(a);b.removeAllRanges();b.addRange(c)}}else(b=document.selection)&&"Control"!=b.type&&(a=b.createRange(),a.collapse(!0),c=b.createRange(),c.setEndPoint("StartToStart",a),c.select())};Graph.prototype.insertRow=function(a,b){for(var c=a.tBodies[0],d=0<c.rows.length?c.rows[0].cells.length:1,c=c.insertRow(b),
 e=0;e<d;e++)mxUtils.br(c.insertCell(-1));return c.cells[0]};Graph.prototype.deleteRow=function(a,b){a.tBodies[0].deleteRow(b)};Graph.prototype.insertColumn=function(a,b){var c=a.tHead;if(null!=c)for(var d=0;d<c.rows.length;d++){var e=document.createElement("th");c.rows[d].appendChild(e);mxUtils.br(e)}c=a.tBodies[0];for(d=0;d<c.rows.length;d++)e=c.rows[d].insertCell(b),mxUtils.br(e);return c.rows[0].cells[0<=b?b:c.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,b){if(0<=b)for(var c=
 a.tBodies[0].rows,d=0;d<c.length;d++)c[d].cells.length>b&&c[d].deleteCell(b)};Graph.prototype.pasteHtmlAtCaret=function(a){var b;if(window.getSelection){if(b=window.getSelection(),b.getRangeAt&&b.rangeCount){b=b.getRangeAt(0);b.deleteContents();var c=document.createElement("div");c.innerHTML=a;a=document.createDocumentFragment();for(var d;d=c.firstChild;)lastNode=a.appendChild(d);b.insertNode(a)}}else(b=document.selection)&&"Control"!=b.type&&b.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,b){b=null!=b?b:a;var c=document.createElement("a");c.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||c.setAttribute("title",a);null!=this.linkTarget&&c.setAttribute("target",this.linkTarget);40<b.length&&(b=b.substring(0,26)+"..."+b.substring(b.length-10));mxUtils.write(c,b);return c};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 b){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(b){b=a.apply(this,arguments);if(mxEvent.isTouchEvent(b.getEvent())&&null==b.getState()){var c=this.getCellAt(b.graphX,b.graphY);null!=c&&this.isSwimlane(c)&&this.hitsSwimlaneContent(c,b.graphX,b.graphY)||(b.state=this.view.getState(c),null!=b.state&&null!=b.state.shape&&(this.container.style.cursor=b.state.shape.node.style.cursor))}null==b.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return b};var b=!1,c=!1,d=!1,e=this.fireMouseEvent;this.fireMouseEvent=function(a,f,g){a==mxEvent.MOUSE_DOWN&&(f=this.updateMouseEvent(f),b=this.isCellSelected(f.getCell()),c=this.isSelectionEmpty(),d=this.popupMenuHandler.isMenuShowing());e.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,e){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==e.getState()||!e.isSource(e.getState().control))&&(this.popupMenuHandler.popupTrigger||!d&&!mxEvent.isMouseEvent(e.getEvent())&&
 (c&&null==e.getCell()&&this.isSelectionEmpty()||b&&this.isCellSelected(e.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var b=[],c=0,d=a.rangeCount;c<d;++c)b.push(a.getRangeAt(c));return b}}else if(document.selection&&
diff --git a/src/main/webapp/js/viewer.min.js b/src/main/webapp/js/viewer.min.js
index 5d9f2c82..fc6c873b 100644
--- a/src/main/webapp/js/viewer.min.js
+++ b/src/main/webapp/js/viewer.min.js
@@ -2351,7 +2351,7 @@ arguments)};h.drawState(this.getView().getState(this.model.root),p);return m};Gr
 b)return null;a=a.parentNode}return a};Graph.prototype.selectNode=function(a){var d=null;if(window.getSelection){if(d=window.getSelection(),d.getRangeAt&&d.rangeCount){var b=document.createRange();b.selectNode(a);d.removeAllRanges();d.addRange(b)}}else(d=document.selection)&&"Control"!=d.type&&(a=d.createRange(),a.collapse(!0),b=d.createRange(),b.setEndPoint("StartToStart",a),b.select())};Graph.prototype.insertRow=function(a,d){for(var b=a.tBodies[0],c=0<b.rows.length?b.rows[0].cells.length:1,b=b.insertRow(d),
 f=0;f<c;f++)mxUtils.br(b.insertCell(-1));return b.cells[0]};Graph.prototype.deleteRow=function(a,d){a.tBodies[0].deleteRow(d)};Graph.prototype.insertColumn=function(a,d){var b=a.tHead;if(null!=b)for(var c=0;c<b.rows.length;c++){var f=document.createElement("th");b.rows[c].appendChild(f);mxUtils.br(f)}b=a.tBodies[0];for(c=0;c<b.rows.length;c++)f=b.rows[c].insertCell(d),mxUtils.br(f);return b.rows[0].cells[0<=d?d:b.rows[0].cells.length-1]};Graph.prototype.deleteColumn=function(a,d){if(0<=d)for(var b=
 a.tBodies[0].rows,c=0;c<b.length;c++)b[c].cells.length>d&&b[c].deleteCell(d)};Graph.prototype.pasteHtmlAtCaret=function(a){var d;if(window.getSelection){if(d=window.getSelection(),d.getRangeAt&&d.rangeCount){d=d.getRangeAt(0);d.deleteContents();var b=document.createElement("div");b.innerHTML=a;a=document.createDocumentFragment();for(var c;c=b.firstChild;)lastNode=a.appendChild(c);d.insertNode(a)}}else(d=document.selection)&&"Control"!=d.type&&d.createRange().pasteHTML(a)};Graph.prototype.createLinkForHint=
-function(a,d){d=null!=d?d:a;var b=document.createElement("a");b.setAttribute("href",this.getAbsoluteUrl(a));this.isCustomLink(a)||b.setAttribute("title",a);null!=this.linkTarget&&b.setAttribute("target",this.linkTarget);40<d.length&&(d=d.substring(0,26)+"..."+d.substring(d.length-10));mxUtils.write(b,d);return b};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
+function(a,d){d=null!=d?d:a;var b=document.createElement("a");b.setAttribute("href",this.getAbsoluteUrl(a));null==a||this.isCustomLink(a)||b.setAttribute("title",a);null!=this.linkTarget&&b.setAttribute("target",this.linkTarget);40<d.length&&(d=d.substring(0,26)+"..."+d.substring(d.length-10));mxUtils.write(b,d);return b};Graph.prototype.initTouch=function(){this.connectionHandler.marker.isEnabled=function(){return null!=this.graph.connectionHandler.first};this.addListener(mxEvent.START_EDITING,function(a,
 d){this.popupMenuHandler.hideMenu()});var a=this.updateMouseEvent;this.updateMouseEvent=function(d){d=a.apply(this,arguments);if(mxEvent.isTouchEvent(d.getEvent())&&null==d.getState()){var b=this.getCellAt(d.graphX,d.graphY);null!=b&&this.isSwimlane(b)&&this.hitsSwimlaneContent(b,d.graphX,d.graphY)||(d.state=this.view.getState(b),null!=d.state&&null!=d.state.shape&&(this.container.style.cursor=d.state.shape.node.style.cursor))}null==d.getState()&&this.isEnabled()&&(this.container.style.cursor="default");
 return d};var d=!1,b=!1,c=!1,f=this.fireMouseEvent;this.fireMouseEvent=function(a,e,g){a==mxEvent.MOUSE_DOWN&&(e=this.updateMouseEvent(e),d=this.isCellSelected(e.getCell()),b=this.isSelectionEmpty(),c=this.popupMenuHandler.isMenuShowing());f.apply(this,arguments)};this.popupMenuHandler.mouseUp=mxUtils.bind(this,function(a,f){this.popupMenuHandler.popupTrigger=!this.isEditing()&&this.isEnabled()&&(null==f.getState()||!f.isSource(f.getState().control))&&(this.popupMenuHandler.popupTrigger||!c&&!mxEvent.isMouseEvent(f.getEvent())&&
 (b&&null==f.getCell()&&this.isSelectionEmpty()||d&&this.isCellSelected(f.getCell())));mxPopupMenuHandler.prototype.mouseUp.apply(this.popupMenuHandler,arguments)})};mxCellEditor.prototype.isContentEditing=function(){var a=this.graph.view.getState(this.editingCell);return null!=a&&1==a.style.html};mxCellEditor.prototype.saveSelection=function(){if(window.getSelection){var a=window.getSelection();if(a.getRangeAt&&a.rangeCount){for(var d=[],b=0,c=a.rangeCount;b<c;++b)d.push(a.getRangeAt(b));return d}}else if(document.selection&&