Bug 319004 CCE caused by PartRenderingEngine assuming a parent eContainer() is an MElementContainer
An MMenu's container could be an MPart, which leads to a CCE in createGui(MUIElement).
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
parent = renderer.getUIContainer(element);
				}
			}
		}
		
		IEclipseContext parentContext = null;
		if (element.getCurSharedRef() != null) {
			MPlaceholder ph = element.getCurSharedRef();
			parentContext = getContext(ph.getParent());
		} else if (parentContext == null && element.getParent() != null) {
			parentContext = getContext(element.getParent());
		} else if (parentContext == null && element.getParent() == null) {
			parentContext = getContext((MElementContainer<MUIElement>) ((EObject) element)
					.eContainer());
		}
		return createGui(element, parent, parentContext);
	}
	private Shell getLimboShell() {
		if (limbo == null) {
			limbo = new Shell(Display.getCurrent(), SWT.NONE);
			limbo.setBackgroundMode(SWT.INHERIT_DEFAULT);
			limbo.setData(ShellActivationListener.DIALOG_IGNORE_KEY,
					Boolean.TRUE);
		}
		return limbo;
	}
	/**
	 * @param element
	 */
	public void removeGui(final MUIElement element) {