Eclipse Juno - Assertion Failed (Problems occurred when invoking code from plug-in: “org.eclipse.jface”.)

Question

I recently installed Eclispe Juno for Java for Android. I usually press . after a class name to know the associated methods, in case I wish to choose some other method instead of one already chosen from this list the following error pops up in the IDE.

How can tell IDE that this is not an error and there is no need to pop this message again and again?

The following is the error log from Eclipse

!ENTRY org.eclipse.jface 4 2 2012-07-01 02:04:29.242
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
org.eclipse.core.runtime.AssertionFailedException: assertion failed: 
    at org.eclipse.core.runtime.Assert.isTrue(Assert.java:110)
    at org.eclipse.core.runtime.Assert.isTrue(Assert.java:96)
    at org.eclipse.ui.texteditor.EditorStatusLine$StatusLineClearer.selectionChanged(EditorStatusLine.java:41)
    at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:164)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
    at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:162)
    at org.eclipse.jface.text.TextViewer.fireSelectionChanged(TextViewer.java:2738)
    at org.eclipse.jface.text.TextViewer.selectionChanged(TextViewer.java:2717)
    at org.eclipse.jface.text.TextViewer.setSelectedRange(TextViewer.java:2402)
    at org.eclipse.jface.text.link.LinkedModeUI.select(LinkedModeUI.java:933)
    at org.eclipse.jface.text.link.LinkedModeUI.switchPosition(LinkedModeUI.java:851)
    at org.eclipse.jface.text.link.LinkedModeUI.next(LinkedModeUI.java:798)
    at org.eclipse.jface.text.link.LinkedModeUI.enter(LinkedModeUI.java:717)
    at org.eclipse.jdt.internal.ui.text.java.ParameterGuessingProposal.apply(ParameterGuessingProposal.java:174)
    at org.eclipse.jdt.internal.ui.text.java.AbstractJavaCompletionProposal.apply(AbstractJavaCompletionProposal.java:477)
    at org.eclipse.jdt.internal.ui.text.java.LazyJavaCompletionProposal.apply(LazyJavaCompletionProposal.java:488)
    at org.eclipse.jface.text.contentassist.CompletionProposalPopup.insertProposal(CompletionProposalPopup.java:940)
    at org.eclipse.jface.text.contentassist.CompletionProposalPopup.insertSelectedProposalWithMask(CompletionProposalPopup.java:891)
    at org.eclipse.jface.text.contentassist.CompletionProposalPopup.verifyKey(CompletionProposalPopup.java:1323)
    at org.eclipse.jface.text.contentassist.ContentAssistant$InternalListener.verifyKey(ContentAssistant.java:808)
    at org.eclipse.jface.text.TextViewer$VerifyKeyListenersManager.verifyKey(TextViewer.java:491)
    at org.eclipse.swt.custom.StyledTextListener.handleEvent(StyledTextListener.java:65)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:774)
    at org.eclipse.swt.custom.StyledText.handleKeyDown(StyledText.java:5932)
    at org.eclipse.swt.custom.StyledText$7.handleEvent(StyledText.java:5629)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
    at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1104)
    at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1100)
    at org.eclipse.swt.widgets.Widget.wmChar(Widget.java:1521)
    at org.eclipse.swt.widgets.Control.WM_CHAR(Control.java:4640)
    at org.eclipse.swt.widgets.Canvas.WM_CHAR(Canvas.java:345)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:4528)
    at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:341)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4976)
    at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
    at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2546)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3756)
    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1022)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:916)
    at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:585)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:540)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

Answer 1

Looks like the problem was caused by Coffee-Byte plugin of Eclipse (plugin used for folding) http://kosiara87.blogspot.in/2011/12/how-to-install-coffee-bytes-plugin-in.html?showComment=1341091754230#c8853438068212069468.

Answer 2

As mentioned before, the problem is caused by the plugin Coffee-Byte plugin for Eclipse. I managed to work-around the problem, for myself at least; disabled everything except Import Statements, Source Headers, Javadocs, and User Defined Regions. I had to manually add regions to the template of methods to get them to fold automatically, but it's a small price to pay for having custom folding.

Also, if anyone is interested in fixing it, the error only occurs if Report problems as you type is enabled in Preferences->Java->Editor. If disabled, then all types of folding work.

Update: I'm currently using Eclipse version Kepler Service Release 1, and build id 20130919-0819. I've re-enabled Normal Methods, Constructors, and Getters and setters; so far, the assertion error hasn't appeared. It seems that the problem has been fixed.