Microsoft // Winlogon 4005 (The Windows logon process has unexpectedly terminated) on one Windows Server 2012 VM with working RDS roles installed

Hello experts,

I have deployed all essential RDS roles and features on one Windows Server 2012 Virtual Machine a few months ago and I recently ran into issues with users not being able to access it through RDP all of a sudden after entering credentials successfully.

Every time that happens I get an event ID Winlogon 4005 (The Windows logon process has unexpectedly terminated). I am also receiving but not all the time event ID 6000 and 6003 referring to being unable to handle critical or normal events from AUinstallAgent.

Any help on this problem would be greatly appreciated.

Thank you in advance for your support.

Massimiliano