Updates to this issue will be posted to http://blogs.technet.com/b/fss/
Last night we pushed out an update that resolves this issue. Updating your engines should resolve this issue and you can go back to your previous configuration.
This is the exact behaviour I am having on my servers as well. When will a fix be produced?
Regards.
We are working on narrowing it down.
If you are in that state now you can call in and sombody will help you get back up and running.
We had some scan engine errors again last night. More Bad defs?
Same issue here. Yesterday around 10am things started to go wrong...
Any solution yet?
Tim