Vaadin 7 NPE Error

Vaadin 6 / 7 / 8
1

Why am I getting this error with Vaadin 7 beta 9

SEVERE: Servlet.service() for servlet [Overlays Application]
in context with path
[/Overlays] threw exception [java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.AbstractClientConnector$CombinedIterator.hasNext(AbstractClientConnector.java:446)
at com.vaadin.server.AbstractClientConnector.attach(AbstractClientConnector.java:554)
at com.vaadin.ui.AbstractComponent.attach(AbstractComponent.java:546)
at com.vaadin.server.AbstractClientConnector.setParent(AbstractClientConnector.java:539)
at com.vaadin.ui.AbstractComponent.setParent(AbstractComponent.java:449)
at com.vaadin.ui.AbstractComponentContainer.addComponent(AbstractComponentContainer.java:202)
at com.vaadin.ui.AbstractOrderedLayout.addComponent(AbstractOrderedLayout.java:83)
at org.vaadin.overlay.OverlayApplication.init(OverlayApplication.java:46)
at com.vaadin.ui.UI.doInit(UI.java:557)

2

Maybe it has to do with the moon. Or your sourcecode. Cant tell for sure, dont see neither at the moment.