[ovirt-users] Ovirt engine General command validation failure.

Hi All, I have a ovirt 4.1.9 self hosted setup with 3 servers. As storage gluster is used in replica 3. I have at a cluster the following error, and this seems to have risen following a routine update (software packages) of the servers. When trying to delete a snapshot of a VM I get at GUI: General command validation failure. Engine logs the attached. Any help is appreciated. Thanx, Alex