"No Remote Desktop License Servers available" error message in Windows Server 2012

You may encounter the following error message when trying to connect to a Windows Server 2012 Remote Desktop Session Host (RDSH) server:
 

The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license.
Please contact the server administrator.

When this error appears, no Remote Desktop connections may be made to the server. This error message may appear even if previous Remote Desktop connections to the server were successful and no recent changes were made to the RDSH server.

A Windows hotfix is available on the Microsoft website and be downloaded here (external link).
 

Additional Information:

The first step in troubleshooting the issue should be to run the RD Licensing Diagnoser tool from Server Manager. This tool checks the existing Remote Desktop licensing configuration for problems and provides troubleshooting suggestions for any that it finds. If the RD Licensing Diagnoser reports the correct licensing information and finds no problems, the issue may be caused by an apparent bug in Windows Server 2012 in which the RDSH server fails to contact the licensing server after the 120-day licensing grace period expires.

If the licensing configuration appears to be correct and the RD Licensing Diagnoser reports no problems, please perform the following steps:

1. Open Registry Editor (regedit).
2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM. Export this registry key to a file before making any changes.
3. Locate the GracePeriod key and either delete or rename it. It may be necessary to take ownership of the key and/or modify its permissions first.
4. Reboot the RDSH server. You should now be able to successfully connect to it.