If you can’t give access rights to a non-existent (at the moment) file - how about simply copying the avast.ovr file to avast.setup, granting the access and then deleting it again?

I guess I should note that I don’t know anything about PG, so I can’t say how (whether) it detects the validity of the file (if it’s just a name, or even the content - the file will be updated during avast! updates).