In https://www-secure.symantec.com/connect/forums/linux-media-server-option-license-violation-huh which is now "locked - Please start a new discussion" I reported being surprised by my Backup Exec 2012 installation accusing me of a license violation (translated from German):
Message: Linux Media Server Option-License Violation
The trial period for the Linux Media Server Option has expired.
You must acquire the Linux Media Server Option or deactivate the devices.
You find additional information in the documentation.
Additional information: Support Database Article V-275-444
I have now analysed the problem a bit further:
In sum, if you enable client side deduplication on a Linux server the licensing check of Backup Exec thinks you are using it as a Media Server and sticks with that even if you later disable it again.
Hope it helps someone.