FabFilter

So I purchased a license for Pro Q 2. However, every time I try to paste the key into the dialogue box, I'm told there's nothing on the clipboard. In fact, I cannot paste anything into the dialogue box because it says my clipboard is empty. I uninstalled and reinstalled, no change. I then attempted to enter the key manually, and after closing Reaper and restarting, I got the same message that I was still running in demo mode. Please help, I've got a mastering job to start within the week and would really benefit from this plugin. Thanks!