Are you running one of the precompiled wallets as per https://www.bitcoinplus.org/wallet.php. In which case - which one ?

I'm not an expert on wallet errors but it sounds like a corrupt database. I would backup your wallet and delete the database file and let the wallet sync up again from the start.

If using Windows, the database is found in the folder - "c:\users\"yourusername"\appdata\roaming\bitcoinplus".