Rev-fx "NO license found"

I am using the UR-22C, but it says that I cannot find REV-FX. This plug-in is already activated. I don’t know the reason. I would appreciate your help.

Hi and welcome to the forum!
As far as I know it is installed along with the Tools for URC. Afterwards you need to activate it on its own by SAM (Steinberg Activation Manager). Please make sure that it is activated and have another look at SAM.
If you already did that - sorry for wasting your time!