The RD Licensing grace period has expired and the service has not registered with a license server with installed licenses. While Windows installed with Terminal Server role it does work without License for 120 Days on trail license, where within 120 days if the License server is not Connected the server will stop accepting connection with below error and event ID
The official solution is to Activate the RDS/TS CAL License server and point the Server to License server with User/Device License and will be resolve the problem
The solution is to delete the REG_BINARY in:
Note: You must first take an ownership and give admins the full rights.
Go to menu Edit > Permissions
After a restart the server will reset the grace period to 120 days.