For ongoing management, rely on proper license server deployment, Group Policy, and regular event log monitoring. Registry hacking should remain the last arrow in your quiver, not the first.
This happens when the RDS service is running. You must stop TermService before certain deletions, especially GracePeriod . rds cal license registry key
October 26, 2023 Subject: Analysis of Remote Desktop Services (RDS) Client Access License (CAL) Registry Keys For ongoing management, rely on proper license server
LicenseKeyStore\00000001-0000-0000-0000-000000000000 : If you change LicensingMode or SpecifiedLicenseServers in
Perform registry edits during maintenance windows to avoid user disconnection. 📍 Where is the RDS CAL License Registry Key?
: If you change LicensingMode or SpecifiedLicenseServers in the registry and find they revert after a reboot, a Group Policy Object (GPO) is enforcing those values. Update the policy via gpedit.msc or your Active Directory domain controller instead.
When Event ID 1003 appears (indicating "The remote desktop client has provided an invalid license"), delete the MSLicensing registry subkey on the client computer, restart the client, and reconnect. If the issue persists, delete the Certificate, X509 Certificate, X509 Certificate2, and X509 Certificate ID entries on the RDSH server, restart the server, and reconnect.