Hello,
What is the difference between configuring the server to use RDS licensing and remote administration mode?
Did you mean mstsc /admin?
it means you are using remote desktop without license, only 2 users are allowed to login.
Notes the server version should be License server > CAL > Session Host. And if you want them work without any issue, you should keep them in the same version (like 2019 license server,2019 cal, 2019 session host)
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