AD / SYSVOL Version Mismatch

I recently had a call from a client, advising they were unable to RDP to a server.
After basic troubleshooting, I discovered that the Windows Firewall was blocking port 3389 from all sources, which was set by server.

I checked the Group Policy in question, and confirmed that Allow inbound Remote Desktop exceptions was configured.




I then confirmed that I could RDP to other servers in the same security groups and OUs.
I ran GPRESULT /R GPreport.html, which returned the following results.

Labtech is in use on this site, and the firewall rules are set from within the Default Domain Policy.

A quick look around advised me that this error for Windows 8/Server 2012 had this hotfix available. Windows 8.1/Server 2012 R2 has this issue fixed with this update

After installing this hotfix, and rebooting the server, I had one rather happy client.