A client backup failed repeated for a few days with a backup to tape – while the same backup completed to disk. Not an unusual circumstance with Backup Exec I’m afraid to report as I have seen this happen in various locations. I noted that some hotfix updates were available for the particular version 12.5 and proceeded to try and bulk update the systems with the 7 or so updates. Every time it failed – and gave the stock error message from Symantec about registering a dll but despite carrying this out – still failure.
I then decided to try and rule out that the first patch update was causing the error – and unselected this but left the others selected. Still faling. So I selected the first hotfix only and retried and low and behold it worked. Repeated this slower but nontheless effective way of getting the hotfixes on and can report that all updates were applied successfully.
Perhaps this may work for you if you find the same backup exec 12.5 issue happening.