Quick answer: Delete the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing registry key on the client machine, then reconnect. If that doesn't stick, update your Remote Desktop client to 8.1 or newer.
That error code — 0X00001B8F — is the classic "your RDP client isn't licensed" message. It shows up when you try to connect to an RDS host (usually Windows Server 2012 R2 or 2016) and the licensing handshake fails. The server looks at the client's license token, decides it's garbage, and kicks you out. I've seen this on Windows 7 machines still running the ancient RDP 7.0 client, and on Windows 10 boxes where the licensing store got corrupted after a bad update.
Here's the thing: the server doesn't actually check if your client has a valid CAL. It checks the client's license store — a registry hive that caches temporary licenses. When that store gets corrupted or holds an old token, the server rejects it. The fix is to reset that store.
- Close all Remote Desktop sessions. Log out of any active RDP connections. If you're at the login screen, just disconnect.
- Open Regedit as Administrator. Press Win+R, type
regedit, right-click it and choose "Run as administrator". - Backup the key (optional but smart). Right-click
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensingand select Export. Save it to a .reg file — you can restore it if something breaks. - Delete the entire MSLicensing key. Right-click it and choose Delete. Confirm when asked. This kills the cached license tokens.
- Close Regedit and reconnect. Launch Remote Desktop Connection (
mstsc) and try to connect again. The client will recreate the key on the fly with fresh tokens.
That usually fixes it. But if you get the same error again after a reboot or a few days later, your client is genuinely too old. Windows 7 with RDP 7.0 won't work with modern RDS servers — the server requires at least RDP 8.1. Update the client:
- Windows 7: Install
KB2592687to get RDP 8.1. Grab it from Microsoft Update Catalog. - Windows 8/8.1: Already has 8.1, but make sure it's fully patched.
- Windows 10/11: The built-in client is fine. Keep it updated via Windows Update.
If the registry delete worked but the error comes back within the hour, your local licensing service is stuck. Restart the Remote Desktop Services service on the client machine. Yes, the client also runs that service — it manages the license store. Open services.msc, find Remote Desktop Services (TermService), right-click and Restart.
Another angle: if you're connecting from a domain-joined machine and the error persists, check the server side. On the RDS host, open Server Manager → Remote Desktop Services → Servers. Look at the licensing status. If it says "Not activated" or "Grace Period", the server itself doesn't have a valid license. Your client isn't the problem — the server's licensing role is broken. You'd need to install and activate the RD Licensing role with proper CALs.
One more scenario I've hit: group policy overriding the licensing mode. On the server, Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Licensing has a setting "Set Remote Desktop licensing mode". If that's set to something other than your actual CAL type (Per User vs Per Device), clients get rejected. Fix the policy and run gpupdate /force on the server.
Prevention is boring but works: keep your RDP clients current. Old clients are the #1 cause of this error. And on the server side, always activate RD Licensing within the 120-day grace period. I've had clients run servers in grace mode for a year — then the error starts appearing randomly on every connection. That's a ticking bomb.
If you're still stuck after all this, check the event log on the client for event ID 1117 from TerminalServices. That'll give you a more detailed reason. But honestly, the registry delete fixes 9 out of 10 cases.