Audiofiles don't work anymore

I’ve update Unity to version 5.1.1f1 and my audiofiles don’t work anymore.

I’ve tried to import the files again, but I get the folowing messages:

“(!) Unspecified error during import AudioClip Assets/splash.wav”

also

“FSBToll.exe has stopped working”

Anyone knows a way to fix this?
Thank you!

I also am having this issue since 5.1.1