Ok so we know the following: F4SE is loading Place.DLL (and mod) is loading. Have you tried placing an object in the allowed zone, then pick it up and move it outside of build zone? From my understanding. without changing .ini it should default to "always on, cannot be turned off" -edit- Can you use any of the other keys? like F1/F2/F3 ? They should produce a message on your screen.