Bitcoin Forum

bool CWallet::Verify(const string& walletFile, string& warningString, string& errorString)
{
    if (!bitdb.Open(GetDataDir()))
    {
        // try moving the database env out of the way
        boost::filesystem::path pathDatabase = GetDataDir() / "database";
        boost::filesystem::path pathDatabaseBak = GetDataDir() / strprintf("database.%d.bak", GetTime());
        try {
            boost::filesystem::rename(pathDatabase, pathDatabaseBak);
            LogPrintf("Moved old %s to %s. Retrying.\n", pathDatabase.string(), pathDatabaseBak.string());
        } catch (const boost::filesystem::filesystem_error&) {
            // failure is ok (well, not really, but it's not worse than what we started with)
        }

        // try again
        if (!bitdb.Open(GetDataDir())) {
            // if it still fails, it probably means we can't even create the database env
            string msg = strprintf(_("Error initializing wallet database environment %s!"), GetDataDir());
            errorString += msg;
            return true;
        }
    }

    if (GetBoolArg("-salvagewallet", false))
    {
        // Recover readable keypairs:
        if (!CWalletDB::Recover(bitdb, walletFile, true))
            return false;
    }

    if (boost::filesystem::exists(GetDataDir() / walletFile))
    {
        CDBEnv::VerifyResult r = bitdb.Verify(walletFile, CWalletDB::Recover);
        if (r == CDBEnv::RECOVER_OK)
        {
            warningString += strprintf(_("Warning: wallet.dat corrupt, data salvaged!"
                                     " Original wallet.dat saved as wallet.{timestamp}.bak in %s; if"
                                     " your balance or transactions are incorrect you should"
                                     " restore from a backup."), GetDataDir());
        }
        if (r == CDBEnv::RECOVER_FAIL)
            errorString += _("wallet.dat corrupt, salvage failed");
    }

    return true;
}

6. Rename wallet.(random numbers).bak back to wallet.dat and start Bitcoin Core again.