SMS Site Backup was unable to back up %1 database %2 to %3.%12 Possible cause: %3 or its directory are not writable. Solution: ...

%11SMS Site Backup was unable to back up %1 database %2 to %3.%12

Possible cause: %3 or its directory are not writable.
Solution: Adjust file attributes and/or permissions on %3 and its directory.

Possible cause: SQL Server problem.
Solution: 
1. Review the immediately preceding status messages from this component about SQL Server errors.
2. Verify that this computer can reach the SQL Server computer.
3. Verify that SQL Server services are running.
4. Verify that SMS can access the SMS site database.
5. Verify that the SMS site database, transaction log, and tempdb are not full.
6. Verify that there are at least 50 SQL Server user connections, plus 5 for each SMS Administrator console.

If the problem persists, check the SQL Server error logs.

Possible cause: An application is using %2 or some component of its path (for example, Windows Explorer may be viewing %2's parent directory.)
Solution: Verify that %2 and its parent directories are not in use by any application.%0