Hello,
Thank you for posting in Q&A forum.
Please try restarting the server and activating again to see if it helps.
In addition, to avoid errors, please follow the instructions on the official documentation to reactivate the Remote Desktop Services License Server.
Reference link: https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/remote-desktop-services-reactivate-deactivate-license-server
Best Regards,
Yanhong Liu
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