This issue occurs only with Backup Exec 2012 with Service Pack 3. On backing up a Sharepoint 2007 or later content DB, the backup may fail with error:
Backup- SharePoint - 80\Content-DB 1 (SQLSERVER1\SQLINSTANCE\WSS_Content)
V-79-57344-794 - Error: Unable to query the Team database meta-data.
Viewing the Sharepoint Web Server debug log for Sharepoint (SPSWRAPPER) the following exception is found:
 11/24/13 15:18:33 !! General Exception in Get Team Site Prefix Info caught in GetTopology()
 11/24/13 15:18:33 General Information:
System.Runtime.InteropServices.COMException (0x80070003): The system cannot find the path specified.
This issue is resolved in Backup Exec 2014 or later versions.
A hotfix is now available for this issue in the current version(s) of the product(s) mentioned in this article. Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.
Backup Exec 2014 Rev 1786 Service Pack 1 (TECH216178).
To resolve this issue and receive the new Backup Exec improvements please upgrade to the current version of Backup Exec.
Perform backups using the Sharepoint Central Admin backup and restore function.