I was missing the <message-bundle>com.test.view.props.test</message-bundle> entry in my faces-config.xml for some code that looked up a default message bundle in my faces application. And I got a NullPointerException java.util.ResourceBundle$CacheKey.calculateHashCode not really explanatory but hey well. .
The Incident Archive: A blog to store my knowledge on the errors that I fix on a daily basis