The Erlide comparison editor yields serious errors when comparing source files through Git.
You may replicate it easily by selecting in the Git history view any two versions (by Ctrl + left-click), then showing the contextual menu and choosing either "Compare with Each Other" or "Compare with Each Other in Tree". You might argue that it is the Git plug-in's fault, but this only happens when the files are opened with the Erlang comparison editor!

They all boil down to this problem:

!ENTRY org.eclipse.jface 4 2 2014-08-13 14:17:23.373
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
java.lang.IllegalArgumentException: Argument not valid
at org.eclipse.swt.SWT.error(SWT.java:4422)
at org.eclipse.swt.SWT.error(SWT.java:4356)
at org.eclipse.swt.SWT.error(SWT.java:4327)
at org.eclipse.swt.custom.StyledText.setStyleRanges(StyledText.java:9820)
at org.eclipse.swt.custom.StyledText.setStyleRanges(StyledText.java:9914)
at org.eclipse.jface.text.TextViewer.applyTextPresentation(TextViewer.java:4884)
at org.eclipse.jface.text.TextViewer.changeTextPresentation(TextViewer.java:4936)
at org.eclipse.jface.text.presentation.PresentationReconciler.applyTextRegionCollection(PresentationReconciler.java:582)
at org.eclipse.jface.text.presentation.PresentationReconciler.processDamage(PresentationReconciler.java:571)
at org.eclipse.jface.text.presentation.PresentationReconciler.access$3(PresentationReconciler.java:567)
at org.eclipse.jface.text.presentation.PresentationReconciler$InternalListener.inputDocumentChanged(PresentationReconciler.java:119)
at org.eclipse.jface.text.TextViewer.fireInputDocumentChanged(TextViewer.java:2894)
at org.eclipse.jface.text.TextViewer.setDocument(TextViewer.java:2943)
at org.eclipse.jface.text.source.SourceViewer.setDocument(SourceViewer.java:642)
at org.eclipse.jface.text.source.SourceViewer.setDocument(SourceViewer.java:576)
at org.eclipse.compare.contentmergeviewer.TextMergeViewer$ContributorInfo.updateViewerDocument(TextMergeViewer.java:778)
at org.eclipse.compare.contentmergeviewer.TextMergeViewer$ContributorInfo.internalSetDocument(TextMergeViewer.java:735)
at org.eclipse.compare.contentmergeviewer.TextMergeViewer$ContributorInfo.setDocument(TextMergeViewer.java:653)
at org.eclipse.compare.contentmergeviewer.TextMergeViewer.updateContent(TextMergeViewer.java:2886)
at org.eclipse.compare.contentmergeviewer.ContentMergeViewer.internalRefresh(ContentMergeViewer.java:743)
at org.eclipse.compare.contentmergeviewer.ContentMergeViewer.inputChanged(ContentMergeViewer.java:643)
at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:292)
at org.eclipse.compare.CompareViewerSwitchingPane.setInput(CompareViewerSwitchingPane.java:277)
at org.eclipse.compare.internal.CompareContentViewerSwitchingPane.setInput(CompareContentViewerSwitchingPane.java:158)
at org.eclipse.compare.CompareEditorInput.internalSetContentPaneInput(CompareEditorInput.java:845)
at org.eclipse.compare.CompareEditorInput.access$8(CompareEditorInput.java:843)
at org.eclipse.compare.CompareEditorInput$11.run(CompareEditorInput.java:786)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.compare.CompareEditorInput.feed1(CompareEditorInput.java:773)
at org.eclipse.compare.CompareEditorInput.access$3(CompareEditorInput.java:772)
at org.eclipse.compare.CompareEditorInput$5.open(CompareEditorInput.java:658)
at org.eclipse.compare.CompareViewerPane.open(CompareViewerPane.java:325)
at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:853)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:50)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:178)
at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:850)
at org.eclipse.compare.structuremergeviewer.DiffTreeViewer.internalOpen(DiffTreeViewer.java:722)
at org.eclipse.compare.structuremergeviewer.DiffTreeViewer.access$3(DiffTreeViewer.java:719)
at org.eclipse.compare.structuremergeviewer.DiffTreeViewer$1.openSelectedChange(DiffTreeViewer.java:178)
at org.eclipse.compare.internal.CompareEditorInputNavigator.openElement(CompareEditorInputNavigator.java:97)
at org.eclipse.compare.internal.CompareEditorInputNavigator.selectChange(CompareEditorInputNavigator.java:66)
at org.eclipse.egit.ui.internal.merge.GitCompareEditorInput.contentsCreated(GitCompareEditorInput.java:214)
at org.eclipse.compare.CompareEditorInput.createContents(CompareEditorInput.java:585)
at org.eclipse.compare.internal.CompareEditor.createCompareControl(CompareEditor.java:462)
at org.eclipse.compare.internal.CompareEditor.createPartControl(CompareEditor.java:414)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl(CompatibilityPart.java:140)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPartControl(CompatibilityEditor.java:99)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:321)
at sun.reflect.GeneratedMethodAccessor41.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:888)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:869)
at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:120)
at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:337)
at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:258)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:162)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:104)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:73)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:55)
at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:127)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:983)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:662)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:766)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:737)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:731)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:715)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl$1.handleEvent(PartServiceImpl.java:92)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:40)
at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:187)
at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:156)
at org.eclipse.swt.widgets.Display.syncExec(Display.java:4734)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application$1.syncExec(E4Application.java:218)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:36)
at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:135)
at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:78)
at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:39)
at org.eclipse.e4.ui.services.internal.events.EventBroker.send(EventBroker.java:81)
at org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged(UIEventPublisher.java:59)
at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:374)
at org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElement(ElementContainerImpl.java:171)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.showElementInWindow(ModelServiceImpl.java:488)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop(ModelServiceImpl.java:454)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop(PartServiceImpl.java:692)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop(PartServiceImpl.java:385)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart(PartServiceImpl.java:1126)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3182)
at org.eclipse.ui.internal.WorkbenchPage.access$23(WorkbenchPage.java:3104)
at org.eclipse.ui.internal.WorkbenchPage$9.run(WorkbenchPage.java:3086)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3081)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3045)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3035)
at org.eclipse.compare.internal.CompareUIPlugin$1.run(CompareUIPlugin.java:562)
at org.eclipse.compare.internal.CompareUIPlugin.syncExec(CompareUIPlugin.java:1419)
at org.eclipse.compare.internal.CompareUIPlugin.internalOpenEditor(CompareUIPlugin.java:573)
at org.eclipse.compare.internal.CompareUIPlugin.openCompareEditor(CompareUIPlugin.java:535)
at org.eclipse.compare.CompareUI.openCompareEditorOnPage(CompareUI.java:168)
at org.eclipse.compare.CompareUI.openCompareEditor(CompareUI.java:137)
at org.eclipse.compare.CompareUI.openCompareEditor(CompareUI.java:121)
at org.eclipse.egit.ui.internal.CompareUtils.openInCompare(CompareUtils.java:293)
at org.eclipse.egit.ui.internal.history.command.CompareVersionsHandler.execute(CompareVersionsHandler.java:76)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:294)
at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:90)
at sun.reflect.GeneratedMethodAccessor44.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:247)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:229)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:149)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:499)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:210)
at org.eclipse.ui.internal.handlers.LegacyHandlerService.executeCommand(LegacyHandlerService.java:343)
at org.eclipse.ui.menus.CommandContributionItem.handleWidgetSelection(CommandContributionItem.java:823)
at org.eclipse.ui.menus.CommandContributionItem.access$21(CommandContributionItem.java:809)
at org.eclipse.ui.menus.CommandContributionItem$5.handleEvent(CommandContributionItem.java:799)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4353)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1061)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4172)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3761)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1151)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:636)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:135)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:382)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:236)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:648)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)
at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
at org.eclipse.equinox.launcher.Main.main(Main.java:1438)

I'm using Eclipse 4.4.0 and Erlide 0.29.1:

!SESSION 2014-08-12 11:36:18.405 -----------------------------------------------
eclipse.buildId=4.4.0.I20140606-1215
java.version=1.7.0_51
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_US
Command-line arguments: -os win32 -ws win32 -arch x86_64