diff --git a/backend/build.gradle b/backend/build.gradle
index dbd93f6..87aaa3f 100644
--- a/backend/build.gradle
+++ b/backend/build.gradle
@@ -4,6 +4,7 @@ buildscript {
     }
     repositories {
         mavenCentral()
+        maven { url "https://oss.sonatype.org/content/repositories/vaadin-snapshots/"}
     }
     dependencies {
         classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
@@ -40,7 +41,9 @@ dependencies {
     compile 'commons-fileupload:commons-fileupload:1.3.2'
     compile 'org.ocpsoft.prettytime:prettytime:3.2.7.Final'
     compile 'net.sf.proguard:proguard-retrace:5.3.3'
-    compile 'org.jfree:jfreechart:1.0.19'
+    compile ('org.jfree:jfreechart:1.0.19') {
+        exclude group:'javax.servlet'
+    }
     //local
     compileOnly project(':annotation')
     apt project(':annotationprocessor')
@@ -59,7 +62,7 @@ configurations {
 
 dependencyManagement {
     imports {
-        mavenBom "com.vaadin:vaadin-bom:8.0.6"
+        mavenBom "com.vaadin:vaadin-bom:8.1-SNAPSHOT"
     }
 }
 
diff --git a/backend/src/main/java/com/faendir/acra/mongod/data/BugRepository.java b/backend/src/main/java/com/faendir/acra/mongod/data/BugRepository.java
new file mode 100644
index 0000000..ff5808e
--- /dev/null
+++ b/backend/src/main/java/com/faendir/acra/mongod/data/BugRepository.java
@@ -0,0 +1,14 @@
+package com.faendir.acra.mongod.data;
+
+import com.faendir.acra.mongod.model.Bug;
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+import java.util.List;
+
+/**
+ * @author Lukas
+ * @since 31.05.2017
+ */
+interface BugRepository extends MongoRepository<Bug, Bug.Identification> {
+    List<Bug> findByApp(String app);
+}
diff --git a/backend/src/main/java/com/faendir/acra/mongod/data/DataManager.java b/backend/src/main/java/com/faendir/acra/mongod/data/DataManager.java
index df60a04..446cc4d 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/data/DataManager.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/data/DataManager.java
@@ -1,6 +1,7 @@
 package com.faendir.acra.mongod.data;
 
 import com.faendir.acra.mongod.model.App;
+import com.faendir.acra.mongod.model.Bug;
 import com.faendir.acra.mongod.model.ProguardMapping;
 import com.faendir.acra.mongod.model.Report;
 import com.mongodb.BasicDBObjectBuilder;
@@ -9,12 +10,9 @@ import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.data.domain.Example;
-import org.springframework.data.domain.ExampleMatcher;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.gridfs.GridFsTemplate;
-import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Component;
 import org.springframework.util.Base64Utils;
 import org.springframework.web.multipart.MultipartFile;
@@ -33,16 +31,18 @@ import java.util.List;
 public class DataManager {
     private final MappingRepository mappingRepository;
     private final ReportRepository reportRepository;
+    private final AppRepository appRepository;
+    private final BugRepository bugRepository;
     private final List<ReportChangeListener> listeners;
     private final GridFsTemplate gridFsTemplate;
     private final Logger logger;
     private final SecureRandom secureRandom;
-    private final AppRepository appRepository;
 
     @Autowired
-    public DataManager(SecureRandom secureRandom, AppRepository appRepository, GridFsTemplate gridFsTemplate, MappingRepository mappingRepository, ReportRepository reportRepository) {
+    public DataManager(SecureRandom secureRandom, AppRepository appRepository, GridFsTemplate gridFsTemplate, MappingRepository mappingRepository, ReportRepository reportRepository, BugRepository bugRepository) {
         this.secureRandom = secureRandom;
         this.appRepository = appRepository;
+        this.bugRepository = bugRepository;
         logger = LoggerFactory.getLogger(DataManager.class);
         this.gridFsTemplate = gridFsTemplate;
         this.mappingRepository = mappingRepository;
@@ -50,45 +50,31 @@ public class DataManager {
         this.listeners = new ArrayList<>();
     }
 
-    public void createNewApp(String name){
+    public synchronized void createNewApp(String name) {
         byte[] bytes = new byte[12];
         secureRandom.nextBytes(bytes);
         appRepository.save(new App(name, Base64Utils.encodeToString(bytes)));
     }
 
-    public List<App> getApps(){
+    public List<App> getApps() {
         return appRepository.findAll();
     }
 
-    public App getApp(String id){
+    public App getApp(String id) {
         return appRepository.findOne(id);
     }
 
-    public void deleteApp(String id){
+    public synchronized void deleteApp(String id) {
         appRepository.delete(id);
-        getReports(id).forEach(this::remove);
+        getReportsForApp(id).forEach(this::deleteReport);
         mappingRepository.delete(getMappings(id));
     }
 
-    public void saveAttachments(String report, List<MultipartFile> attachments) {
-        for (MultipartFile a : attachments) {
-            try {
-                gridFsTemplate.store(a.getInputStream(), a.getOriginalFilename(), a.getContentType(), new BasicDBObjectBuilder().add("reportId", report).get());
-            } catch (IOException e) {
-                logger.warn("Failed to load attachment", e);
-            }
-        }
-    }
-
     public List<GridFSDBFile> getAttachments(String report) {
         return gridFsTemplate.find(new Query(Criteria.where("metadata.reportId").is(report)));
     }
 
-    public void removeAttachments(String report) {
-        gridFsTemplate.delete(new Query(Criteria.where("metadata.reportId").is(report)));
-    }
-
-    public void addMapping(String app, int version, String mappings) {
+    public synchronized void addMapping(String app, int version, String mappings) {
         mappingRepository.save(new ProguardMapping(app, version, mappings));
     }
 
@@ -97,33 +83,74 @@ public class DataManager {
     }
 
     public List<ProguardMapping> getMappings(String app) {
-        return mappingRepository.findAll(Example.of(new ProguardMapping(app, -1, null), ExampleMatcher.matchingAny()));
+        return mappingRepository.findByApp(app);
     }
 
-    public void newReport(JSONObject content) {
-        newReport(content, Collections.emptyList());
+    public void newReport(String app, JSONObject content) {
+        newReport(app, content, Collections.emptyList());
     }
 
-    public void newReport(JSONObject content, List<MultipartFile> attachments) {
-        Report report = reportRepository.save(new Report(content, SecurityContextHolder.getContext().getAuthentication().getName()));
-        saveAttachments(report.getId(), attachments);
+    public synchronized void newReport(String app, JSONObject content, List<MultipartFile> attachments) {
+        Report report = reportRepository.save(new Report(content, app));
+        for (MultipartFile a : attachments) {
+            try {
+                gridFsTemplate.store(a.getInputStream(), a.getOriginalFilename(), a.getContentType(), new BasicDBObjectBuilder().add("reportId", report.getId()).get());
+            } catch (IOException e) {
+                logger.warn("Failed to load attachment", e);
+            }
+        }
+        Bug bug = bugRepository.findOne(new Bug.Identification(report.getStacktrace().hashCode(), report.getVersionCode()));
+        if (bug == null) {
+            bugRepository.save(new Bug(app, report.getStacktrace(), report.getVersionCode()));
+        }
         listeners.forEach(ReportChangeListener::onChange);
     }
 
-    public List<Report> getReports(String app) {
-        return reportRepository.findAll(Example.of(new Report(null, app)));
+    public List<Report> getReportsForApp(String app) {
+        return reportRepository.findByApp(app);
     }
 
     public Report getReport(String id) {
         return reportRepository.findOne(id);
     }
 
-    public void remove(Report report){
+    public synchronized void deleteReport(Report report) {
         reportRepository.delete(report);
-        removeAttachments(report.getId());
+        gridFsTemplate.delete(new Query(Criteria.where("metadata.reportId").is(report.getId())));
+        if(reportRepository.countByBug(report.getStacktrace(), report.getVersionCode()) == 0){
+            bugRepository.delete(bugRepository.findOne(new Bug.Identification(report.getStacktrace().hashCode(), report.getVersionCode())));
+        }
         listeners.forEach(ReportChangeListener::onChange);
     }
 
+    public List<Bug> getBugs(String app) {
+        return bugRepository.findByApp(app);
+    }
+
+    public List<Report> getReportsForBug(Bug bug) {
+        return reportRepository.findByBug(bug.getStacktrace(), bug.getVersionCode());
+    }
+
+    public int countReportsForBug(Bug bug){
+        return reportRepository.countByBug(bug.getStacktrace(), bug.getVersionCode());
+    }
+
+    public String retrace(Report report){
+        ProguardMapping mapping = getMapping(report.getApp(), report.getVersionCode());
+        if (mapping != null) {
+            try {
+                return ReportUtils.retrace(report.getStacktrace(), mapping);
+            } catch (IOException ignored) {
+            }
+        }
+        return report.getStacktrace();
+    }
+
+    public void setBugSolved(Bug bug, boolean solved){
+        bug.setSolved(solved);
+        bugRepository.save(bug);
+    }
+
     public boolean addListener(ReportChangeListener reportChangeListener) {
         return listeners.add(reportChangeListener);
     }
@@ -135,4 +162,5 @@ public class DataManager {
     public interface ReportChangeListener {
         void onChange();
     }
+
 }
diff --git a/backend/src/main/java/com/faendir/acra/mongod/data/MappingRepository.java b/backend/src/main/java/com/faendir/acra/mongod/data/MappingRepository.java
index 92ed790..a560587 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/data/MappingRepository.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/data/MappingRepository.java
@@ -2,10 +2,15 @@ package com.faendir.acra.mongod.data;
 
 import com.faendir.acra.mongod.model.ProguardMapping;
 import org.springframework.data.mongodb.repository.MongoRepository;
+import org.springframework.data.mongodb.repository.Query;
+
+import java.util.List;
 
 /**
  * @author Lukas
  * @since 19.05.2017
  */
 interface MappingRepository extends MongoRepository<ProguardMapping, ProguardMapping.MetaData> {
+    @Query("{id.app:?0}")
+    List<ProguardMapping> findByApp(String app);
 }
diff --git a/backend/src/main/java/com/faendir/acra/mongod/data/ReportRepository.java b/backend/src/main/java/com/faendir/acra/mongod/data/ReportRepository.java
index 43ea3fe..1096e5e 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/data/ReportRepository.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/data/ReportRepository.java
@@ -1,11 +1,22 @@
 package com.faendir.acra.mongod.data;
 
 import com.faendir.acra.mongod.model.Report;
+import org.springframework.data.mongodb.repository.CountQuery;
 import org.springframework.data.mongodb.repository.MongoRepository;
+import org.springframework.data.mongodb.repository.Query;
+
+import java.util.List;
 
 /**
  * @author Lukas
  * @since 22.03.2017
  */
 interface ReportRepository extends MongoRepository<Report, String> {
+    List<Report> findByApp(String app);
+
+    @Query("{content.map.STACK_TRACE:?0,content.map.APP_VERSION_CODE:?1}")
+    List<Report> findByBug(String stacktrace, int versionCode);
+
+    @CountQuery("{content.map.STACK_TRACE:?0,content.map.APP_VERSION_CODE:?1}")
+    int countByBug(String stacktrace, int versionCode);
 }
diff --git a/backend/src/main/java/com/faendir/acra/mongod/data/ReportUtils.java b/backend/src/main/java/com/faendir/acra/mongod/data/ReportUtils.java
index 5f8b93f..27b278e 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/data/ReportUtils.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/data/ReportUtils.java
@@ -1,6 +1,5 @@
 package com.faendir.acra.mongod.data;
 
-import com.faendir.acra.mongod.model.Bug;
 import com.faendir.acra.mongod.model.ProguardMapping;
 import com.faendir.acra.mongod.model.Report;
 import org.apache.commons.io.FileUtils;
@@ -14,7 +13,6 @@ import java.io.StringReader;
 import java.io.StringWriter;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Locale;
@@ -26,18 +24,6 @@ import java.util.Locale;
 public final class ReportUtils {
     private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX", Locale.ENGLISH);
 
-    public static List<Bug> getBugs(List<Report> reports) {
-        List<Bug> bugs = new ArrayList<>();
-        for (Report report : reports) {
-            bugs.stream().filter(bug -> bug.is(report)).findAny().orElseGet(() -> {
-                Bug bug = new Bug(report);
-                bugs.add(bug);
-                return bug;
-            }).getReports().add(report);
-        }
-        return bugs;
-    }
-
     public static Date getDateFromString(String s) {
         try {
             return dateFormat.parse(s);
@@ -56,4 +42,8 @@ public final class ReportUtils {
         return writer.toString();
     }
 
+    public static Date getLastReportDate(List<Report> reports) {
+        return reports.stream().map(Report::getDate).reduce((d1, d2) -> d1.after(d2) ? d1 : d2).orElse(new Date());
+    }
+
 }
diff --git a/backend/src/main/java/com/faendir/acra/mongod/model/Bug.java b/backend/src/main/java/com/faendir/acra/mongod/model/Bug.java
index 0771485..d28a354 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/model/Bug.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/model/Bug.java
@@ -1,41 +1,58 @@
 package com.faendir.acra.mongod.model;
 
-import java.util.ArrayList;
-import java.util.Date;
-import java.util.List;
+import org.springframework.data.mongodb.core.index.Indexed;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+import java.io.Serializable;
 
 /**
  * @author Lukas
  * @since 13.05.2017
  */
+@Document
 public class Bug {
-    private List<Report> reports;
-    private String trace;
-    private int versionCode;
+    private Identification id;
+    @Indexed
+    private String app;
+    private boolean solved;
+    private String stacktrace;
 
-    public Bug(Report report){
-        reports = new ArrayList<>();
-        this.trace = report.getStacktrace();
-        this.versionCode = report.getVersionCode();
+    public Bug(){
+    }
+
+    public Bug(String app, String stacktrace, int versionCode){
+        this.id = new Identification(stacktrace.hashCode(), versionCode);
+        this.app = app;
+        this.stacktrace = stacktrace;
     }
 
     public boolean is(Report report){
-        return report.getStacktrace().equals(trace) && report.getVersionCode() == versionCode;
+        return report.getStacktrace().hashCode() == id.stacktraceHash && report.getVersionCode() == id.versionCode;
     }
 
-    public List<Report> getReports() {
-        return reports;
+    public boolean isSolved() {
+        return solved;
     }
 
-    public Date getLastDate(){
-        return reports.stream().map(Report::getDate).reduce((d1, d2) -> d1.after(d2) ? d1 : d2).orElse(new Date());
+    public void setSolved(boolean solved) {
+        this.solved = solved;
     }
 
-    public String getTrace() {
-        return trace;
+    public String getStacktrace() {
+        return stacktrace;
     }
 
     public int getVersionCode() {
-        return versionCode;
+        return id.versionCode;
+    }
+
+    public static class Identification implements Serializable {
+        private int stacktraceHash;
+        private int versionCode;
+
+        public Identification(int stacktraceHash, int versionCode) {
+            this.stacktraceHash = stacktraceHash;
+            this.versionCode = versionCode;
+        }
     }
 }
diff --git a/backend/src/main/java/com/faendir/acra/mongod/model/Report.java b/backend/src/main/java/com/faendir/acra/mongod/model/Report.java
index 2879cad..d0e62fc 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/model/Report.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/model/Report.java
@@ -1,13 +1,11 @@
 package com.faendir.acra.mongod.model;
 
-import com.faendir.acra.mongod.data.DataManager;
 import com.faendir.acra.mongod.data.ReportUtils;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.springframework.data.mongodb.core.index.Indexed;
 import org.springframework.data.mongodb.core.mapping.Document;
 
-import java.io.IOException;
 import java.util.Date;
 import java.util.function.Function;
 
@@ -21,7 +19,6 @@ public class Report {
     @Indexed
     private String app;
     private JSONObject content;
-    private String deObfuscatedTrace;
 
     public Report() {
     }
@@ -30,7 +27,6 @@ public class Report {
         this.content = content;
         this.app = app;
         id = content == null ? null : getValueSafe("REPORT_ID", content::getString, "");
-        deObfuscatedTrace = null;
     }
 
     public JSONObject getContent() {
@@ -45,23 +41,12 @@ public class Report {
         return id;
     }
 
-    public String getStacktrace() {
-        return getValueSafe("STACK_TRACE", content::getString, "");
+    public String getApp() {
+        return app;
     }
 
-    public String getDeObfuscatedStacktrace(DataManager dataManager){
-        if (deObfuscatedTrace != null) {
-            return deObfuscatedTrace;
-        }
-        ProguardMapping mapping = dataManager.getMapping(app, getVersionCode());
-        if (mapping != null) {
-            try {
-                deObfuscatedTrace = ReportUtils.retrace(getStacktrace(), mapping);
-                return deObfuscatedTrace;
-            } catch (IOException ignored) {
-            }
-        }
-        return getStacktrace();
+    public String getStacktrace() {
+        return getValueSafe("STACK_TRACE", content::getString, "");
     }
 
     public int getVersionCode() {
diff --git a/backend/src/main/java/com/faendir/acra/mongod/user/UserManager.java b/backend/src/main/java/com/faendir/acra/mongod/user/UserManager.java
index d22cef9..ffcd0ec 100644
--- a/backend/src/main/java/com/faendir/acra/mongod/user/UserManager.java
+++ b/backend/src/main/java/com/faendir/acra/mongod/user/UserManager.java
@@ -47,9 +47,11 @@ public class UserManager {
     public User getUser(String username) {
         User user = userRepository.findOne(username);
         if (user == null && defaultUser.equals(username)) {
-            return getDefaultUser();
+            user = getDefaultUser();
+        }
+        if(user != null) {
+            ensureValidPermissions(user);
         }
-        ensureValidPermissions(user);
         return user;
     }
 
diff --git a/backend/src/main/java/com/faendir/acra/service/ReportService.java b/backend/src/main/java/com/faendir/acra/service/ReportService.java
index 96fde04..34877a3 100644
--- a/backend/src/main/java/com/faendir/acra/service/ReportService.java
+++ b/backend/src/main/java/com/faendir/acra/service/ReportService.java
@@ -17,6 +17,7 @@ import org.springframework.web.multipart.MultipartHttpServletRequest;
 import javax.servlet.ServletException;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.security.Principal;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -35,14 +36,14 @@ public class ReportService {
 
     @PreAuthorize("hasRole('REPORTER')")
     @RequestMapping(value = "/report", consumes = MediaType.APPLICATION_JSON_VALUE)
-    public void report(@RequestBody String content) throws IOException {
+    public void report(@RequestBody String content, Principal principal) throws IOException {
         JSONObject jsonObject = new JSONObject(content);
-        dataManager.newReport(jsonObject);
+        dataManager.newReport(principal.getName(), jsonObject);
     }
 
     @PreAuthorize("hasRole('REPORTER')")
     @RequestMapping(value = "/report", consumes = "multipart/mixed")
-    public ResponseEntity report(MultipartHttpServletRequest request) throws IOException, ServletException {
+    public ResponseEntity report(MultipartHttpServletRequest request, Principal principal) throws IOException, ServletException {
         MultiValueMap<String, MultipartFile> fileMap = request.getMultiFileMap();
         List<MultipartFile> files = fileMap.get(null);
         JSONObject jsonObject = null;
@@ -56,7 +57,7 @@ public class ReportService {
             }
         }
         if(jsonObject != null) {
-            dataManager.newReport(jsonObject, attachments);
+            dataManager.newReport(principal.getName(), jsonObject, attachments);
             return ResponseEntity.ok().build();
         }else {
             return ResponseEntity.badRequest().build();
diff --git a/backend/src/main/java/com/faendir/acra/ui/BackendUI.java b/backend/src/main/java/com/faendir/acra/ui/BackendUI.java
index 8393023..5ad24f3 100644
--- a/backend/src/main/java/com/faendir/acra/ui/BackendUI.java
+++ b/backend/src/main/java/com/faendir/acra/ui/BackendUI.java
@@ -14,6 +14,7 @@ import com.vaadin.ui.Alignment;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.HorizontalLayout;
 import com.vaadin.ui.LoginForm;
+import com.vaadin.ui.Notification;
 import com.vaadin.ui.UI;
 import com.vaadin.ui.VerticalLayout;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -54,15 +55,14 @@ public class BackendUI extends UI {
         }
     }
 
-    private boolean login(String username, String password) {
+    private void login(String username, String password) {
         try {
             Authentication token = authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(username.toLowerCase(), password));
             VaadinService.reinitializeSession(VaadinService.getCurrentRequest());
             SecurityContextHolder.getContext().setAuthentication(token);
             showMain();
-            return true;
         } catch (AuthenticationException ex) {
-            return false;
+            Notification.show("Unknown username/password combination", Notification.Type.ERROR_MESSAGE);
         }
     }
 
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/Overview.java b/backend/src/main/java/com/faendir/acra/ui/view/Overview.java
index 14ce32c..652736b 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/Overview.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/Overview.java
@@ -64,7 +64,7 @@ public class Overview extends NamedView {
         grid.setSizeFull();
         grid.setSelectionMode(Grid.SelectionMode.NONE);
         grid.addColumn(App::getName, "Name");
-        grid.addColumn(app -> dataManager.getReports(app.getId()).size(), "Reports");
+        grid.addColumn(app -> dataManager.getReportsForApp(app.getId()).size(), "Reports");
         VerticalLayout layout = new VerticalLayout(grid);
         if(SecurityUtils.hasRole(UserManager.ROLE_ADMIN)){
             Button add = new Button("New App", e -> addApp());
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/ReportView.java b/backend/src/main/java/com/faendir/acra/ui/view/ReportView.java
index 179b06d..705999a 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/ReportView.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/ReportView.java
@@ -87,7 +87,7 @@ public class ReportView extends NamedView {
         summaryGrid.addComponents(new Label("Version", ContentMode.PREFORMATTED), new Label(report.getVersionName(), ContentMode.PREFORMATTED));
         summaryGrid.addComponents(new Label("Email", ContentMode.PREFORMATTED), new Label(report.getUserEmail(), ContentMode.PREFORMATTED));
         summaryGrid.addComponents(new Label("Comment", ContentMode.PREFORMATTED), new Label(report.getUserComment(), ContentMode.PREFORMATTED));
-        summaryGrid.addComponents(new Label("De-obfuscated Stacktrace", ContentMode.PREFORMATTED), new Label(report.getDeObfuscatedStacktrace(dataManager), ContentMode.PREFORMATTED));
+        summaryGrid.addComponents(new Label("De-obfuscated Stacktrace", ContentMode.PREFORMATTED), new Label(dataManager.retrace(report), ContentMode.PREFORMATTED));
         summaryGrid.addComponents(new Label("Attachments", ContentMode.PREFORMATTED), attachments);
         summaryGrid.setDefaultComponentAlignment(Alignment.MIDDLE_LEFT);
         summaryGrid.setSizeFull();
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/base/MyCheckBox.java b/backend/src/main/java/com/faendir/acra/ui/view/base/MyCheckBox.java
new file mode 100644
index 0000000..a304344
--- /dev/null
+++ b/backend/src/main/java/com/faendir/acra/ui/view/base/MyCheckBox.java
@@ -0,0 +1,19 @@
+package com.faendir.acra.ui.view.base;
+
+import com.vaadin.ui.CheckBox;
+
+/**
+ * @author Lukas
+ * @since 31.05.2017
+ */
+public class MyCheckBox extends CheckBox {
+    public MyCheckBox(boolean value, ValueChangeListener<Boolean> changeListener) {
+        this(value, true, changeListener);
+    }
+
+    public MyCheckBox(boolean value, boolean enabled, ValueChangeListener<Boolean> changeListener) {
+        setValue(value);
+        setEnabled(enabled);
+        addValueChangeListener(changeListener);
+    }
+}
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/base/ReportList.java b/backend/src/main/java/com/faendir/acra/ui/view/base/ReportList.java
index 2da0571..5814a5b 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/base/ReportList.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/base/ReportList.java
@@ -18,10 +18,12 @@ import java.util.function.Supplier;
  * @since 14.05.2017
  */
 public class ReportList extends MyGrid<Report> implements DataManager.ReportChangeListener {
+    public static final String CAPTION = "Reports";
     private final Supplier<List<Report>> reportSupplier;
 
     public ReportList(String app, NavigationManager navigationManager, DataManager dataManager, Supplier<List<Report>> reportSupplier) {
-        super("Reports", reportSupplier.get());
+        super(CAPTION, reportSupplier.get());
+        setId(CAPTION);
         this.reportSupplier = reportSupplier;
         setSizeFull();
         setSelectionMode(SelectionMode.NONE);
@@ -31,7 +33,7 @@ public class ReportList extends MyGrid<Report> implements DataManager.ReportChan
         addColumn(Report::getPhoneModel, "Device");
         addColumn(report -> report.getStacktrace().split("\n", 2)[0], "Stacktrace").setExpandRatio(1);
         if (SecurityUtils.hasPermission(app, Permission.Level.EDIT)) {
-            addColumn(report -> "Delete", new ButtonRenderer<>(e -> dataManager.remove(e.getItem())));
+            addColumn(report -> "Delete", new ButtonRenderer<>(e -> dataManager.deleteReport(e.getItem())));
         }
         addItemClickListener(e -> navigationManager.navigateTo(ReportView.class, e.getItem().getId()));
         addAttachListener(e -> dataManager.addListener(this));
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/tabs/BugTab.java b/backend/src/main/java/com/faendir/acra/ui/view/tabs/BugTab.java
index e809e62..f70d5ef 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/tabs/BugTab.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/tabs/BugTab.java
@@ -3,15 +3,24 @@ package com.faendir.acra.ui.view.tabs;
 import com.faendir.acra.mongod.data.DataManager;
 import com.faendir.acra.mongod.data.ReportUtils;
 import com.faendir.acra.mongod.model.Bug;
+import com.faendir.acra.mongod.model.Permission;
+import com.faendir.acra.security.SecurityUtils;
 import com.faendir.acra.ui.NavigationManager;
+import com.faendir.acra.ui.view.base.MyCheckBox;
 import com.faendir.acra.ui.view.base.MyGrid;
 import com.faendir.acra.ui.view.base.ReportList;
 import com.faendir.acra.util.Style;
 import com.faendir.acra.util.TimeSpanRenderer;
 import com.vaadin.event.selection.SelectionEvent;
 import com.vaadin.shared.data.sort.SortDirection;
+import com.vaadin.ui.Alignment;
+import com.vaadin.ui.CheckBox;
+import com.vaadin.ui.Component;
 import com.vaadin.ui.VerticalLayout;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 /**
  * @author Lukas
  * @since 17.05.2017
@@ -22,19 +31,29 @@ public class BugTab extends VerticalLayout implements DataManager.ReportChangeLi
     private final NavigationManager navigationManager;
     private final DataManager dataManager;
     private final MyGrid<Bug> bugs;
+    private final CheckBox hideSolved;
 
     public BugTab(String app, NavigationManager navigationManager, DataManager dataManager) {
         this.app = app;
         this.navigationManager = navigationManager;
         this.dataManager = dataManager;
-        bugs = new MyGrid<>(null, ReportUtils.getBugs(dataManager.getReports(app)));
+        hideSolved = new CheckBox("Hide solved", true);
+        hideSolved.addValueChangeListener(e -> onChange());
+        addComponent(hideSolved);
+        setComponentAlignment(hideSolved, Alignment.MIDDLE_RIGHT);
+        bugs = new MyGrid<>(null, getBugs());
         bugs.setSizeFull();
-        bugs.addColumn(bug -> bug.getReports().size(), "Reports");
-        bugs.sort(bugs.addColumn(Bug::getLastDate, new TimeSpanRenderer(), "Latest Report"), SortDirection.DESCENDING);
+        bugs.addColumn(dataManager::countReportsForBug, "Reports");
+        bugs.sort(bugs.addColumn(bug -> ReportUtils.getLastReportDate(dataManager.getReportsForBug(bug)), new TimeSpanRenderer(), "Latest Report"), SortDirection.DESCENDING);
         bugs.addColumn(Bug::getVersionCode, "Version");
-        bugs.addColumn(bug -> bug.getTrace().split("\n", 2)[0], "Stacktrace").setExpandRatio(1);
+        bugs.addColumn(bug -> bug.getStacktrace().split("\n", 2)[0], "Stacktrace").setExpandRatio(1);
         bugs.addSelectionListener(this::handleBugSelection);
+        bugs.addComponentColumn(bug -> new MyCheckBox(bug.isSolved(), SecurityUtils.hasPermission(app, Permission.Level.EDIT), e -> {
+            dataManager.setBugSolved(bug, e.getValue());
+            onChange();
+        })).setCaption("Solved");
         addComponent(bugs);
+        setExpandRatio(bugs, 1);
         Style.NO_PADDING.apply(this);
         setSizeFull();
         setCaption(CAPTION);
@@ -43,14 +62,28 @@ public class BugTab extends VerticalLayout implements DataManager.ReportChangeLi
     }
 
     private void handleBugSelection(SelectionEvent<Bug> e) {
-        if (getComponentCount() == 2) {
-            removeComponent(getComponent(1));
+        for (Component component : this) {
+            if (ReportList.CAPTION.equals(component.getId())) {
+                removeComponent(component);
+            }
         }
-        e.getFirstSelectedItem().ifPresent(bug -> addComponent(new ReportList(app, navigationManager, dataManager, bug::getReports)));
+        e.getFirstSelectedItem().ifPresent(bug -> {
+            ReportList reportList = new ReportList(app, navigationManager, dataManager, () -> dataManager.getReportsForBug(bug));
+            addComponent(reportList);
+            setExpandRatio(reportList, 1);
+        });
     }
 
     @Override
     public void onChange() {
-        bugs.setItems(ReportUtils.getBugs(dataManager.getReports(app)));
+        bugs.setItems(getBugs());
+    }
+
+    private List<Bug> getBugs() {
+        List<Bug> bugs = dataManager.getBugs(app);
+        if (hideSolved.getValue()) {
+            return bugs.stream().filter(bug -> !bug.isSolved()).collect(Collectors.toList());
+        }
+        return bugs;
     }
 }
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/tabs/ReportTab.java b/backend/src/main/java/com/faendir/acra/ui/view/tabs/ReportTab.java
index 0a4d971..dde2e8e 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/tabs/ReportTab.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/tabs/ReportTab.java
@@ -10,6 +10,6 @@ import com.faendir.acra.ui.view.base.ReportList;
  */
 public class ReportTab extends ReportList {
     public ReportTab(String app, NavigationManager navigationManager, DataManager dataManager) {
-        super(app, navigationManager, dataManager, () -> dataManager.getReports(app));
+        super(app, navigationManager, dataManager, () -> dataManager.getReportsForApp(app));
     }
 }
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/tabs/StatisticsTab.java b/backend/src/main/java/com/faendir/acra/ui/view/tabs/StatisticsTab.java
index efde160..2d4e76c 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/tabs/StatisticsTab.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/tabs/StatisticsTab.java
@@ -48,7 +48,7 @@ public class StatisticsTab extends HorizontalLayout {
         numberField.setValue(30);
         numberField.setMinValue(5);
         numberField.addValueChangeListener(e -> setTimeChart(e.getValue()));
-        reports = dataManager.getReports(app);
+        reports = dataManager.getReportsForApp(app);
         timeLayout = new VerticalLayout(numberField);
         Style.NO_PADDING.apply(timeLayout);
         addComponent(timeLayout);
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/user/PermissionEditor.java b/backend/src/main/java/com/faendir/acra/ui/view/user/PermissionEditor.java
deleted file mode 100644
index d284a1e..0000000
--- a/backend/src/main/java/com/faendir/acra/ui/view/user/PermissionEditor.java
+++ /dev/null
@@ -1,86 +0,0 @@
-package com.faendir.acra.ui.view.user;
-
-import com.faendir.acra.mongod.data.DataManager;
-import com.faendir.acra.mongod.model.Permission;
-import com.faendir.acra.ui.view.base.MyGrid;
-import com.vaadin.data.HasValue;
-import com.vaadin.shared.Registration;
-import com.vaadin.ui.ComboBox;
-import com.vaadin.ui.Grid;
-import org.vaadin.hene.popupbutton.PopupButton;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.stream.Collectors;
-
-/**
- * @author Lukas
- * @since 20.05.2017
- */
-public class PermissionEditor extends PopupButton implements HasValue<Collection<Permission>> {
-
-    private Collection<Permission> items;
-    private MyGrid<Permission> grid;
-
-    public PermissionEditor(DataManager dataManager) {
-        super("Editor");
-        items = new ArrayList<>();
-        grid = new MyGrid<>(null, items);
-        grid.addColumn(permission -> dataManager.getApp(permission.getApp()).getName(), "App");
-        ComboBox<Permission.Level> levelComboBox = new ComboBox<>("", Arrays.asList(Permission.Level.values()));
-        grid.addColumn(permission -> permission.getLevel().name(), "Level")
-                .setEditorBinding(grid.getEditor().getBinder().bind(levelComboBox, Permission::getLevel, (permission, level) -> {
-                    Collection<Permission> newValue = items.stream().map(p -> new Permission(p.getApp(), p.getLevel())).collect(Collectors.toList());
-                    newValue.stream().filter(p -> p.getApp().equals(permission.getApp())).findAny().ifPresent(p -> p.setLevel(level));
-                    setValue(newValue, true);
-                }));
-        grid.getEditor().setEnabled(true).setBuffered(false);
-        grid.setSelectionMode(Grid.SelectionMode.NONE);
-        setContent(grid);
-        setPopupVisible(true);
-    }
-
-    @Override
-    public void setValue(Collection<Permission> value) {
-        setValue(value, false);
-    }
-
-    private void setValue(Collection<Permission> value, boolean userOriginated) {
-        Collection<Permission> oldValue = items;
-        items = value;
-        grid.setItems(items);
-        grid.setHeightByRows(items.size());
-        fireEvent(new ValueChangeEvent<>(this, oldValue, userOriginated));
-    }
-
-    @Override
-    public Collection<Permission> getValue() {
-        return items;
-    }
-
-    @Override
-    public void setRequiredIndicatorVisible(boolean requiredIndicatorVisible) {
-    }
-
-    @Override
-    public boolean isRequiredIndicatorVisible() {
-        return false;
-    }
-
-    @Override
-    public Registration addValueChangeListener(ValueChangeListener<Collection<Permission>> listener) {
-        return addListener(ValueChangeEvent.class, listener,
-                ValueChangeListener.VALUE_CHANGE_METHOD);
-    }
-
-    @Override
-    public void setReadOnly(boolean readOnly) {
-
-    }
-
-    @Override
-    public boolean isReadOnly() {
-        return false;
-    }
-}
diff --git a/backend/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java b/backend/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
index 70d6243..439d4cb 100644
--- a/backend/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
+++ b/backend/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
@@ -1,18 +1,20 @@
 package com.faendir.acra.ui.view.user;
 
 import com.faendir.acra.mongod.data.DataManager;
+import com.faendir.acra.mongod.model.App;
+import com.faendir.acra.mongod.model.Permission;
 import com.faendir.acra.mongod.model.User;
 import com.faendir.acra.mongod.user.UserManager;
 import com.faendir.acra.security.SecurityUtils;
+import com.faendir.acra.ui.view.base.MyCheckBox;
 import com.faendir.acra.ui.view.base.MyGrid;
 import com.faendir.acra.ui.view.base.NamedView;
 import com.faendir.acra.util.Style;
-import com.vaadin.data.Binder;
 import com.vaadin.navigator.ViewChangeListener;
 import com.vaadin.server.UserError;
 import com.vaadin.spring.annotation.UIScope;
 import com.vaadin.ui.Button;
-import com.vaadin.ui.CheckBox;
+import com.vaadin.ui.ComboBox;
 import com.vaadin.ui.Grid;
 import com.vaadin.ui.PasswordField;
 import com.vaadin.ui.TextField;
@@ -22,7 +24,7 @@ import com.vaadin.ui.Window;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
-import java.util.stream.Collectors;
+import java.util.Arrays;
 
 /**
  * @author Lukas
@@ -54,17 +56,28 @@ public class UserManagerView extends NamedView {
     @Override
     public void enter(ViewChangeListener.ViewChangeEvent event) {
         userGrid = new MyGrid<>("Users", userManager.getUsers());
-        userGrid.getEditor().setEnabled(true).setBuffered(false);
         userGrid.setSelectionMode(Grid.SelectionMode.NONE);
         userGrid.addColumn(User::getUsername, "Username");
-        Binder<User> binder = userGrid.getEditor().getBinder();
-        userGrid.addColumn(user -> user.getRoles().contains(UserManager.ROLE_ADMIN) ? "Yes" : "No").setCaption("Admin")
-                .setEditorBinding(binder.forField(new CheckBox())
-                        .withValidator(bool -> bool || !binder.getBean().getUsername().equals(SecurityUtils.getUsername()), "Cannot revoke own admin privileges")
-                        .bind(user -> user.getRoles().contains(UserManager.ROLE_ADMIN), userManager::setAdmin));
-        userGrid.addColumn(this::getPermissionString, "App Permissions")
-                .setEditorBinding(userGrid.getEditor().getBinder().bind(new PermissionEditor(dataManager), User::getPermissions,
-                        ((user, permissions) -> permissions.forEach(p -> userManager.setPermission(user, p.getApp(), p.getLevel())))));
+        userGrid.addComponentColumn(user -> new MyCheckBox(user.getRoles().contains(UserManager.ROLE_ADMIN), e -> {
+            if (!e.getValue() && user.getUsername().equals(SecurityUtils.getUsername())) {
+                MyCheckBox checkBox = ((MyCheckBox) e.getComponent());
+                checkBox.setComponentError(new UserError("Cannot revoke own admin privileges"));
+                checkBox.setValue(true);
+            } else {
+                userManager.setAdmin(user, e.getValue());
+            }
+        })).setCaption("Admin");
+        for (App app : dataManager.getApps()) {
+            userGrid.addComponentColumn(user -> {
+                Permission permission = user.getPermissions().stream().filter(p -> p.getApp().equals(app.getId())).findAny().orElseThrow(IllegalStateException::new);
+                ComboBox<Permission.Level> levelComboBox = new ComboBox<>(null, Arrays.asList(Permission.Level.values()));
+                levelComboBox.setEmptySelectionAllowed(false);
+                levelComboBox.setValue(permission.getLevel());
+                levelComboBox.addValueChangeListener(e -> userManager.setPermission(user, permission.getApp(), e.getValue()));
+                return levelComboBox;
+            }).setCaption("Access Permission for " + app.getName());
+        }
+        userGrid.setRowHeight(42);
         Button newUser = new Button("New User", e -> newUser());
         VerticalLayout layout = new VerticalLayout(userGrid, newUser);
         layout.setExpandRatio(userGrid, 1);
@@ -76,12 +89,6 @@ public class UserManagerView extends NamedView {
         Style.apply(this, Style.PADDING_LEFT, Style.PADDING_RIGHT, Style.PADDING_BOTTOM);
     }
 
-    private String getPermissionString(User user) {
-        return user.getPermissions().stream()
-                .map(permission -> dataManager.getApp(permission.getApp()).getName() + ": " + permission.getLevel().name())
-                .collect(Collectors.joining(", "));
-    }
-
     private void newUser() {
         Window window = new Window("New User");
         TextField name = new TextField("Username");