Fix ERROR_CTX_LICENSE_EXPIRED (0x1B90) on Windows Remote Desktop

1. The RDS License Server Certificate Expired (Most Common)

I know this error is infuriating — it usually shows up right when you're about to connect to a remote desktop, and then boom, nothing. You see ERROR_CTX_LICENSE_EXPIRED (0x00001B90) and your session dies.

This most often happens because the license server's own certificate has expired. On Windows Server 2012 R2 and 2016, I've seen this kick in after the 90-day grace period. The fix is to renew the self-signed certificate that the Remote Desktop Licensing Manager uses.

1. Open Remote Desktop Licensing Manager (search for it on the license server).
2. Right-click your license server and select Properties.
3. Go to the Connection Method tab and choose Web Browser (or whatever method you used originally).
4. Click Renew and follow the wizard. If your server has internet access, it grabs a new certificate automatically.
5. If it fails, manually download the renewal from the Microsoft Licensing Portal (you'll need your license agreement number).

Once renewed, restart the Remote Desktop Services service.

net stop TermService && net start TermService

This fixes 80% of cases I've handled. The error vanishes and users reconnect immediately.

2. The RDS Licensing Mode Is Wrong (Per User vs Per Device)

Another common trigger: you've installed the licenses, but the RDS deployment is set to the wrong licensing mode. This tripped me up the first time too. You get 0x1B90 if the mode doesn't match the actual licenses you installed.

For example, you bought Per User licenses but your server is set to Per Device. Or vice versa. Windows checks this at connection time, and if it doesn't match, it refuses to hand out a license.

Checking and fixing the licensing mode

1. Open Server Manager on the RD Session Host (the machine users connect to).
2. Go to Remote Desktop Services > Collections.
3. Find your collection (usually named something like "RDSH Collection" or "Default").
4. Right-click it and select Properties.
5. In the Licensing tab, set the mode to match your actual license type. If you have Per User licenses, select Per User. If Per Device, select Per Device.
6. Also ensure the license server is listed correctly. Click Add and enter the license server's FQDN or IP.

After changing the mode, run gpupdate /force on the session host to force the policy update. Then restart the Remote Desktop Services service again.

A quick tip: If you're not sure what licenses you installed, open RD Licensing Manager and check the "Installed Licenses" tab. It lists the type and count.

3. The License Server Itself Is Down or Misconfigured

Sometimes the error is a red herring — the license server is unreachable. I've seen this when the server's IP changed, the service stopped, or DNS points to a dead server.

Verify the license server is alive

1. On the RD Session Host, open PowerShell as admin.
2. Run:

   Get-WmiObject -Class Win32_TSLicenseServer -ComputerName "YOUR_LICENSE_SERVER"

3. If it returns nothing or an error, the license server isn't responding.
4. Ping the license server by name and IP. If it fails, fix DNS or add a hosts file entry.
5. Check that the Remote Desktop Licensing service is running on the license server.

Reinstalling the license server as a last resort

If the license server is beyond repair (corrupted database, failed upgrade), remove and reinstall the role:

1. On the license server, open Server Manager.
2. Remove the Remote Desktop Licensing role.
3. Reboot.
4. Re-add the role.
5. Activate the server with Microsoft and install your licenses.
6. Reconfigure the RD Session Host to point to this server.

This is nuclear but works when everything else fails. Expect a 30-minute downtime.

Quick-Reference Summary Table

I've used these three fixes dozens of times across Server 2012 R2, 2016, and 2019. You'll likely resolve the error with step one. If not, move to step two, then step three. Don't waste time on fancy workarounds — these are the real fixes.