Hello,
This error is usually related to licensing requirements for remote desktop services.
To solve this problem, you can:
Check the Grace period status: By default, Windows Server provides a grace period during which a limited number of users (typically two) can connect to the server using RDP without requiring additional licensing. Once this grace period expires, you need to configure a Remote Desktop License Server or reduce the number of concurrent RDP sessions to comply with the licensing requirements.
Configure a Remote Desktop License Server: If you have a valid Remote Desktop services license server, make sure it is properly configured and accessible to the server.
Purchase Additional licenses: If you need more than the default number of RDP sessions, you need to purchase additional Remote Desktop Services Client Access Licenses (CALs).
Check the RDS CAL type: Make sure you have the correct RDS CAL type (per user or per device) according to your usage scenario.
Restart the server: After changing the license configuration, restart the server to ensure that all Settings are applied correctly.