Error message 7285:save:Volumes selected... on networker

Hello!

Since a few days I receive the following message on Networker 8.0.1

7285:save: Volumes selected do not support the use of VSS. NetWorker software will save the files using the legacy backup method.

No snapshot will be taken.

86705:save: Successfully established DFA session with adv_file device for save-set ID '********'

The files are stored on cifs shares hosted on a celerra ns-120.

There were no changes depending the backup jobs and the shares during this week.

Any idea what could cause this problem?

Greetings