Maximum number of licensed sessions are already in use for this applet

[hind]

I'm trying to connect but unfortunately im getting a frequent message saying that Maximum number of licensed sessions are already in use for this applet. Please contact your system administrator, which is irritating me. 

What is the solution of this issue? I need a clear answer please I'm too fed up. 

[spuluka]

Are you connecting with the RDP web interface?

This error there generally means you don't have enough licensed users.  By default only 2 users are included for the RDP add-on and more would need to be purchased for simultaneous users.