While supporting a network where multiple remote employees connect to their Windows 10 desktops through RDP, I've run into a vexing problem. Several users have reported black screens upon RDP connection, and all of them are on Windows 11. This post serves to document our troubleshooting journey and the temporary fixes we've found.
The Issue
- Affected Population: Remote staff operating on Windows 11.
- How They Connect: Via L2TP VPN, followed by RDP to their Windows 10 desktops.
- What Happens: A black screen with an active mouse cursor is all they see upon connecting.
What's Not Broken
- No RDP issues for clients using Windows 10.
- Linux users also report smooth RDP sessions.
Technical Specifics
- Port Information: Port 3389 is open for both UDP and TCP.
- Protocols: If UDP is disabled, connecting via TCP shows an unchanging initial desktop frame.
Troubleshooting Steps
- Toggling WDDM: Ineffective.
- Switching RemoteFX On/Off: Also ineffective.
- Reducing Client-Side RDP Resolution: No change.
- Altering Bit Depth: Inconsequential.
- Bitmap Caching Disabled: No improvement.
Temporary Solutions
- Reverting to Windows 10: This works but comes with its own set of problems.
- Adopting Linux: This has proven to be an effective and stable solution.
- Third-Party RDP Clients: Tested mRemoteNG; it's not stable although it avoids the black screen issue.
Additional Points
- The stability of internet connections has been confirmed through continuous Quick Assist sessions.
- We've been compelled to downgrade multiple Windows 11 machines back to Windows 10 due to this issue.
Final Thoughts
After trying a multitude of fixes, it's becoming increasingly clear that this is likely an unresolved bug affecting RDP between Windows 11 and Windows 10. It's perplexing that this has been an issue for several months without a resolution from Microsoft. We're left with no option but to rely on less-than-perfect workarounds for now.
