Windows Server: Remote Desktop Error When Establishing a Remote Desktop Connection

The following error message may appear when users attempt to establish a Remote Desktop connection to a server:

"The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license."

• Remote Desktop Licensing Manager shows that Remote Desktop (RD) client access licenses (CAL) are installed on the licensing server.
• The Remote Desktop License Diagnoser shows that the correct licensing server is in use.
• Most notably, the RD CALs listed in Remote Desktop Licensing Manager do not list an operating system version, as shown in this image:
  Figure 1: Screenshot of Remote Desktop Licensing Manager showing installed CALs with no operating system version

• Upgrade the operating system on the licensing server to match the version of the installed RD CALs. This requires a valid, unused Windows Server license and product key.
• Install the RD Licensing role service on an existing server that is running the newer operating system. Migrate the RD CALs to it and configure the Remote Desktop Services deployment to use it as a licensing server.
• Contact the Microsoft Clearinghouse and have the RD CALs downgraded to the version running on the licensing server. Dell Support can assist with contacting the Microsoft Clearinghouse.