Got the issue too... Black screen with white borders...
Music is running in the background from the game but nothing i can do except do a reset of PC.
This is REALLY annoying... Running Win10 64-bit and a 4 Gig Asus radeon R9 270X, Had no problem b4 patch, now i can get to the mainscreen with the message with the level 12 and all that and then Black screen/white borders...
Please DO FIX ASAP!!!
Edit:
Ok. Now my game works again...
Don't get the black/white screen anymore... don't know what was fixed but something was ;) Thanks for a Quick fix WoWs team!!!!