You might want to check the agent logs to see what happens when the task is received. Assuming you are getting the other tasks (e.g. run script), you should see this on the client in the Tasks tab. Then, when you assign a copy file task, or whatever, you should also see THAT arrive, even if it fails. If it does not arrive, then the problem is server-side (e.g. no licenses). If it does arrive, and then fails, the problem is obviously client-side.
In the latter scenario, you would check the agent logs to see what happend when the task arrived. it might say something like missing interpreter, or give a fault or... I don't know. But that's what you're going to have to look for, or the agent helping you. :P