Hello,
Thank you for posting in the Microsoft community forum.
The message is a known symptom reported by Microsoft:
First confirm your equipment environment so that we can accurately analyze the cause of the problem:
Operating system version of the server.
Whether the device is added to a domain.
For Windows Server 2019 as an example, you can first check the RD Licensing configuration
You can use any of the following methods to check the RD Licensing configuration, depending on how you manage your servers.
I hope this helps. If you have any follow-up questions, please contact us.
Best regards
Jacen