The remote session was disconnected because there are no Terminal Server license servers available to provide a license

Problem:

User could not connect to any Citrix application, and whenever launching a Citrix application, it throws the error " The remote session was disconnected because there are no Terminal Server license servers available to provide a license"

Solution:

To Resolve the License error remove the MSLicensing registry key on the user desktop by following the below steps.

1. On the client, open Registry Editor. To open Registry Editor, click Start, click Run, type regedit, and then click OK.
2. Locate, and then click, the following key in the registry:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing

3. On the Registry menu, click Export Registry File.
4. In the File name box, type mslicensingbackup, and then click Save. 
5. If you need to restore this registry key in the future, double-click mslicensingbackup.reg.
6. On the Edit menu, click Delete, and then click Yes to confirm the deletion of the MSLicensing registry subkey.
7. Close Registry Editor, and then restart the computer (when the client is restarted, the missing registry key is rebuilt).
8. Now check the Citrix applications.