It doesn't say that at all. It says your exe must be named ff7.exe not REnamed. And if you haven't messed with anything, your ff7 exe name would already be ff7.exe.
I'm not sure what file it is you're trying to rename or why. In Settings>General Settings your ff7 exe must point to your ff7 game install folder\ff7.exe which is provided to you by/with 7H. If you're trying to rename a Steam exe or something (like ff7_en.exe), don't do that.