Due to the antivirus program, the GRT backup of Hyper V virtual machine gets hung during "Updating Catalogs" while the backup is going to B2D
The Hyper V host becomes unresponsive to any new command and after sometime it gets off the network as well (cannot ping).
1. Try excluding the Backup Exec installation directory and the backup destination from the antivirus online scan resolves the issue.
2. Try disabling the antivirus service.