When a backup is performed using the SQL Backup Pro extended stored procedure, the following error may occur:
This error occurs when the old xp_sqlbackup.dll file has not been freed. To fix the problem, uninstall and reinstall the SQL Backup Pro server components:
Do not uninstall and reinstall the server components more than once, or the SQL Backup Agent service may be removed. If this happens, install the server components manually by running SQBServerSetup.exe. For more information, see Installing the server components manually.
You may also need to find the SQL Backup Agent service in Services, as above, and enable and restart it manually: