Unable to restore SharePoint farm with Backup Exec - Farm Topolgy appears to be locked and job repeatedly fails

Hi All

I'm attempting a full restore of a SharePoint 2010 farm, single server housed on the same server as the SQL server that holds the SharePoint databases. Backup and restore is via Backup Exec, the backup job was carried out via BE 2012 and the Restore is via BE 2104. The server I'm attempting to restore to has also been restored by using the system state and a copy of the drives from the original source server - hence its pretty much a clone of the source server.

Irrespective of the account used to run the restore job I'm seeing repeated failures with the error "Unable to lock the Microsoft SharePoint Farm Topology. You must unlock the farm topology and retry the job".

By restoring the admin databases directly by taking a SQL backup of the source databases and restoring these to the server I'm attempting to restore SharePoint to I have succeeded in bringing the SharePoint admin console back to life, none of the sites are in a locked state, and they can be locked and unlocked both via the admin console or via Powershell. Locking and unlocking the makes no difference.

Any ideas where I can look to from here, could the above error be a cryptic Backup Exec error that doesn't actually mean what it says?