Bug 329930 Resetting a perspective while its active part is not defined in the perspective causes the perspective to not have an active part after the reset
1. Window > Show View > Console 2. Window > Reset Perspective... > OK 3. No parts are active.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
MElementContainer<MUIElement> container = getContainer();
				return findContainer(container, element);
			}
			return placeholder.getParent();
		}
		return parent;
	}
	private MElementContainer<MUIElement> findContainer(MElementContainer<?> container,
			MUIElement element) {
		for (Object child : container.getChildren()) {
			if (child == element) {
				return (MElementContainer<MUIElement>) container;
			} else if (child instanceof MPlaceholder) {
				MPlaceholder placeholder = (MPlaceholder) child;
				MUIElement ref = placeholder.getRef();
				if (ref == element) {
					return (MElementContainer<MUIElement>) container;
				} else if (ref instanceof MElementContainer<?>) {
					MElementContainer<MUIElement> match = findContainer((MElementContainer<?>) ref,
							element);
					if (match != null) {
						return match;
					}
				}
			} else if (child instanceof MElementContainer<?>) {
				MElementContainer<MUIElement> match = findContainer((MElementContainer<?>) child,
						element);
				if (match != null) {
					return match;
				}