You can use mstsc /admin to work around the following licensing error when attempting to connect with RDP to an Azure VM:

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

Please contact the server administrator. 

Using mstsc /admin disables licensing for that connection only, so you could only ever have a maximum of two connections made with /admin at the same time. But it is helpful in this scenario where the 120-day Remote Desktop licensing grace period has expired and you need to access the VM to install RDS licenses. Note that if you encounter this error and you don’t need more than two RDP connections to the VM at the same time, you can use Server Manager to remove the RDS role so licensing is not enforced and you go back to having a maximum of two administrative connections.

Note that you can also edit the RDP file in a text editor and add /admin to achieve the same thing as running mstsc /admin.

full address:s:MYVM.cloudapp.net:57362 /admin

See also:

Use command line parameters with Remote Desktop Connection
http://windows.microsoft.com/en-us/windows/command-line-parameters-remote-desktop-connection/