Fix "No Remote Desktop License Servers Available" on Windows Server

Symptoms

• Users see: "The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license."
• Administrators can still connect with mstsc /admin, but regular users can't
• It typically starts about four months after the Remote Desktop Session Host role was installed

Why it happens

When you install the Remote Desktop Session Host role, Windows allows connections for a 120-day grace period without licenses. After that, every user or device needs a Remote Desktop Services Client Access License (RDS CAL), issued by a server running the RD Licensing role. If no license server is configured, reachable and holding valid CALs, connections are refused.

Step 1: Check the grace period and current configuration

On the session host, open PowerShell as Administrator. This shows how many grace-period days remain (0 means it has expired):

(Get-WmiObject -Namespace root\cimv2\terminalservices -Class Win32_TerminalServiceSetting).GetGracePeriodDays().DaysLeft

Then run the RD Licensing Diagnoser, which reports exactly what's misconfigured:

lsdiag.msc

Step 2: Make sure a license server exists and is activated

1. On the server that will issue licenses (often the session host itself in small deployments), install the Remote Desktop Licensing role service through Server Manager.
2. Open Remote Desktop Licensing Manager (licmgr.exe), right-click the server and choose Activate Server.

Step 3: Install the right CALs

In Licensing Manager, right-click the server and choose Install Licenses, then enter your license agreement or pack details. Check two things:

• Version: RDS CALs must be the same version as the session host's operating system, or newer. Windows Server 2016 CALs won't license a Windows Server 2022 or 2025 session host. This catches many people right after an upgrade.
• Type: CALs are either Per User or Per Device, and the type must match the licensing mode you configure in Step 4. Per User tracking relies on Active Directory, so standalone (workgroup) servers should use Per Device.

Step 4: Point the session host at the license server

If you use an RDS deployment (configured through Server Manager's Remote Desktop Services pages): open Remote Desktop Services → Overview → Tasks → Edit Deployment Properties → RD Licensing, choose the licensing mode and add the license server.

For a standalone session host, use Group Policy, either local (gpedit.msc) or a domain GPO. Go to:

Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Licensing

• Use the specified Remote Desktop license servers: Enabled, with the license server's name or IP address
• Set the Remote Desktop licensing mode: Enabled, set to Per User or Per Device to match your CALs

Apply the policy and restart the session host during a maintenance window:

gpupdate /force

Step 5: Verify

1. Rerun lsdiag.msc. It should report no licensing problems.
2. Connect as a regular user from a client machine.
3. In Licensing Manager, Per Device licenses should show as issued after the first connection. (Per User CALs aren't enforced the same way, but should still be tracked for compliance.)

Still seeing the error?

• The license server can't be reached: confirm name resolution and that firewalls allow the session host to reach the license server.
• Wrong CAL version after an in-place upgrade: see our guide to Windows Server 2016 end of support for upgrade licensing considerations.
• Mode mismatch: Per Device CALs installed while the session host is set to Per User, or the reverse.

We manage Remote Desktop Services environments every day, including licensing. If you'd rather hand it off, our hourly support is ideal for a one-time fix like this.