After you enter your License you need to restart the PhoneSystem. You have to do the Same when downgrading or problems like these usually show up.
Another thing to check is if you Installed the K-Lite Codec pack on that specific machine.
If you have you need to go to :
Start > All programs > K-Lite Codec Pack > Configuration > ffdshow audio decoder > Direct Show Control > Move the Merit Slide Bar to : Dont Use.
If it persists, give the PBX a couple of minutes after the Restart before making calls.
Can you call the IVR? Does the IVR Register when you start the PBX? Do you hear the ringing tone when calling the IVR? Does it give you a busy tone when calling the IVR?