MyEclipse 2017 CI errors with Preferences window - eclipse

Question

Resolved: I resolved this by just creating a new workspace. I'm not sure exactly what happened to corrupt my old workspace, hard to tell and hard to resolve.
I just installed MyEclipse 2017 CI and converted my old 2016 CI workspace. I did some messing around with my theme, not really sure exactly what I did, nothing out of the ordinary, restarted my Eclipse client, and now I get errors when I try to navigate to Window > Preferences.
Specifically, when I first click Preferences, I get this error, and the Preferences window doesn't open:
!ENTRY org.eclipse.ui 4 0 2017-04-25 15:56:19.105
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.IllegalStateException: ScrollBarsProvider not initialized
at org.eclipse.swt.custom.ScrolledComposite.createScrollBar(ScrolledComposite.java:819)
at org.eclipse.swt.custom.ScrolledComposite.<init>(ScrolledComposite.java:161)
at org.eclipse.jface.preference.PreferenceDialog.createPageContainer(PreferenceDialog.java:491)
at org.eclipse.jface.preference.PreferenceDialog.createDialogArea(PreferenceDialog.java:412)
at org.eclipse.jface.dialogs.Dialog.createContents(Dialog.java:767)
at org.eclipse.jface.preference.PreferenceDialog.access$5(PreferenceDialog.java:1)
at org.eclipse.jface.preference.PreferenceDialog.lambda$0(PreferenceDialog.java:344)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog.createContents(PreferenceDialog.java:343)
at org.eclipse.jface.window.Window.create(Window.java:426)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1095)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.createDialogOn(WorkbenchPreferenceDialog.java:102)
at org.eclipse.ui.dialogs.PreferencesUtil.createPreferenceDialogOn(PreferencesUtil.java:192)
at org.eclipse.ui.dialogs.PreferencesUtil.createPreferenceDialogOn(PreferencesUtil.java:116)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:62)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:473)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:565)
at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:397)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4410)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4228)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3816)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1121)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1022)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:150)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:687)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:604)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:138)
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:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:673)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:610)
at org.eclipse.equinox.launcher.Main.run(Main.java:1519)
If I click Preferences a second time, it will open, but none of the preference screens display. When I click a tab to get a screen to display, I get a popup that states "The currently displayed page contains invalid values", along with the following error:
!ENTRY org.eclipse.jface 4 2 2017-04-25 16:02:11.702
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
java.lang.IllegalArgumentException: Argument cannot be null
at org.eclipse.swt.SWT.error(SWT.java:4514)
at org.eclipse.swt.SWT.error(SWT.java:4448)
at org.eclipse.swt.SWT.error(SWT.java:4419)
at org.eclipse.swt.widgets.Widget.error(Widget.java:482)
at org.eclipse.swt.widgets.Widget.checkParent(Widget.java:291)
at org.eclipse.swt.widgets.Widget.<init>(Widget.java:158)
at org.eclipse.swt.widgets.Control.<init>(Control.java:110)
at org.eclipse.swt.widgets.Scrollable.<init>(Scrollable.java:82)
at org.eclipse.swt.widgets.Composite.<init>(Composite.java:96)
at org.eclipse.jface.preference.PreferencePage.createControl(PreferencePage.java:223)
at org.eclipse.jface.preference.PreferenceDialog.createPageControl(PreferenceDialog.java:1430)
at org.eclipse.jface.preference.PreferenceDialog$9.run(PreferenceDialog.java:1197)
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:173)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1189)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:608)
at org.eclipse.jface.preference.PreferenceDialog$5.lambda$0(PreferenceDialog.java:656)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog$5.selectionChanged(PreferenceDialog.java:653)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:878)
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:173)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:875)
at org.eclipse.jface.viewers.StructuredViewer.handlePostSelect(StructuredViewer.java:1244)
at org.eclipse.jface.viewers.StructuredViewer$5.widgetSelected(StructuredViewer.java:1270)
at org.eclipse.jface.util.OpenStrategy.firePostSelectionEvent(OpenStrategy.java:265)
at org.eclipse.jface.util.OpenStrategy.access$5(OpenStrategy.java:259)
at org.eclipse.jface.util.OpenStrategy$1.lambda$1(OpenStrategy.java:431)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:182)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4203)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3819)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:818)
at org.eclipse.jface.window.Window.open(Window.java:794)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:211)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:63)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:473)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:565)
at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:397)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4410)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4228)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3816)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1121)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1022)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:150)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:687)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:604)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:138)
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:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:673)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:610)
at org.eclipse.equinox.launcher.Main.run(Main.java:1519)

Answer 1

Not sure what is going on there, looks like the window model got messed up. In the interests of getting back to work, I suggest either opening a New Window (Window->New Window0 then closing the old window. If that doesn't work, try opening MyEclipse on a new, empty, workspace and import your projects from the old workspace. You may have to reset some preferences and define servers again but at least you'd be up and running! If you make some theme changes again, make a note of what you did as that seems like the source of the problem.