Just wait until it downloads it again. Should be fine.
That was my solution as well... BUT as i have noticed, the re-downloading is adding (again) massive data to C: . I already have a 21gb big blockchain data there and only 4gb left of free space. This won't go far.
My second solution would be to save the wallet.bin file and then erase everything and re-install a new client. But this will take days - so i wait, maybe somebody has a better solution...?
EDIT: It's done - solution found!