Ue4, BUG; Crash and than never again Opening

It seems Ue4, 4.17 is not really Stabable at BP, theres the SECOND Time that my UE4 Crash when im Work, and Compile at BP, and than it Crashes, and my WHOLE PROJECT; is for Trash because its not Opening Anymore, and the Assets are Opend, are just Corrupted.

oh and a Comment to this: on 4.15.3 it Crashes not.