i also have this problem ago, just wait more time, it will be ok after 10 min.
but you should withdraw all coin to a new wallet.
but you should withdraw all coin to a new wallet.
hm I had it open for while but I'll try again, thanks for the tip!
edit: alrighty! took a while longer but worked now
You should also click the Command Line Banking button on the opened client using the damaged wallet and type repairwallet and press return. It may well have some coins to reclaim that never made it onto the blockchain in an earlier attempt.
As xchange suggests it's best to move any coins to a brand new wallet after getting that startup message because otherwise it tries to rescan on every startup.