Hello Steve and welcome to the RH community.
First of all, you should never ever move, copy or rename RH
files outside of RH unless you want to spend lots of time putting
things right. If you do, RH throws a wobbly because it knows
nothing about what has been done.
I suspect your problem is that the Graphics EN folder is in
fact not empty or that there are still references to one of more of
the files in it inside your RH project. Do a search using RH
inbuilt tool and you should find where the references are.