Bug 63268 error while activating view
I'm not sure what caused this behaviour. I created a workspace this morning, imported a few projects, and ran the UI Test Suite. However, I got an error when trying to activate the Hierarchy view (by clicking on it). The error looks like an infinite loop. The trace is over 800 lines long, so I'll attach it in a minute.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
private ToggleLinkingAction fToggleLinkingAction;
	private HistoryDropDownAction fHistoryDropDownAction;
	private ToggleOrientationAction[] fToggleOrientationActions;
	private EnableMemberFilterAction fEnableMemberFilterAction;
	private ShowQualifiedTypeNamesAction fShowQualifiedTypeNamesAction;
	private AddMethodStubAction fAddStubAction;
	private FocusOnTypeAction fFocusOnTypeAction;
	private FocusOnSelectionAction fFocusOnSelectionAction;
	private CompositeActionGroup fActionGroups;
	private SelectAllAction fSelectAllAction;
	
	private WorkingSetFilterActionGroup fWorkingSetActionGroup;
	private Job fRestoreStateJob;
	
	public TypeHierarchyViewPart() {
		fSelectedType= null;
		fInputElement= null;
		fIsVisible= false;
		fIsRefreshRunnablePosted= false;
		fSelectInEditor= true;
		fRestoreStateJob= null;
		
		fHierarchyLifeCycle= new TypeHierarchyLifeCycle();
		fTypeHierarchyLifeCycleListener= new ITypeHierarchyLifeCycleListener() {
			public void typeHierarchyChanged(TypeHierarchyLifeCycle typeHierarchy, IType[] changedTypes) {
				doTypeHierarchyChanged(typeHierarchy, changedTypes);
			}
		};
		fHierarchyLifeCycle.addChangedListener(fTypeHierarchyLifeCycleListener);