I've had a similar issue before caused by the directory being in Program Files. Moving all of the game files to the Desktop worked for me. Maybe try that?
Don't forget the serial on the game page. This user appeared to have a similar problem. Maybe try that solution?
This worked! Being in Program Files seemed to prevent it from creating Editor.ini, and thus saving the game path I set. Plus, I can actually edit Game.ini now. Thank you.