Backup of a virtual machine using the Agent for VMware Virtual Infrastructure (AVVI) completes with the following exception when GRT is enabled: "V-79-57344-38721- Failed to mount one or more virtual disk images"

hi all,

BE 2012

i'm backing up via vCenter 5 VM's for 4 of them i'm getting the error message Backup of a virtual machine using the Agent for VMware Virtual Infrastructure (AVVI) completes with the following exception when GRT is enabled: "V-79-57344-38721- Failed to mount one or more virtual disk images"

found a TECHNOTE  that this should be solved with HOTFIX 180964 but it's allready installed and all Remote Agent's are updated.

what's strange the one server where it's working I'm able to run GRT restore's and the server has a VM icon all 4 where the exceptions is being displayed are with an windows server icon and no restore possible as it's in never backed up status, but I'm able to restore the whole .vmdk for all of 5 servers.

any ideas guys ?

thank you