This error message indicates data corruption. Use the Check Integrity option in the SQL Server Blackbaud Management Console to validate the database.
If it indicates data corruption:
     
    • Restore from a backup from prior to the data corruption.
      Note: We cannot determine when the data was corrupted. Contact your IT manager to restore backups until a clean copy is found.
    •  Contact an outside vendor that specializes in data recovery to recover your data (if possible).