Local or server-side firewalls blocking RDP traffic or mismatched security layers (SSL/TLS vs. RDP Security Layer). Driver Conflicts: Issues with the Microsoft Remote Display Adapter or outdated GPU drivers. Permissions:

The RD Connection Broker (tssdis.exe) service failing to start automatically after a reboot.

Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options

typically points to a general connectivity failure where the remote host is unreachable

In on the remote computer, go to View > Show hidden devices .