How old was your restore? It is possible that in between your restore point and now the AD computer account password changed and the VM is no longer able to log in to AD to obtain its policies.
You can check to see if this is the case on the DCs in the site (AD site if you have multiple) in their event log.
You could also look at the attributes of the computer object in AD and see when the "pwdLastSet" time is. If its aftyouths date of your restore point that is likely the issue. Boot the VM with the network unplugged, wait for it to time out, log in using local administrator, re-enable NIC and rejoin the system to the domain.