I edited the Preference feature in my app and could not start the app. I was getting the following error:
java.lang.IllegalArgumentException: no layout registered with default id (LayoutRegistry.DEFAULT_LAYOUT_ID) or no layout activated over branding extension.
Turns out that the cookies have got themselves in a muddle and need to be deleted. I don't like to delete all my cookies so I (in IE8) opened Tools -> Internet options -> Browsing history -> Settings -> View files. This shows all the temp files. I sorted by last changed date and deleted the files which looked like 'Cookie@127.0.0.1'
Then it all worked again.