Vanilla 2.0.8 Dashboard CSS broken

I have a site using 2.0.8 and suddenly there seems to be a problem with Dashboard. It has changed it's look and the sign out icons have a link which says "FR" over them which prevents clicking but goes to a page called /fr and gives 404 error.
There's also a link which says "vanilla" (to left) which looks like it has a missing image in the code which links to another missing page called /en with the same result - a 404 error.
Could anyone explain whay has happened and, more importantly, how I get it back to normal.
Cheers
Dave
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