That dev mode unlocker hasn't worked in a long time. It was killed by the dev. All it did was link to code designed to test the upcoming content for Act IV. Once act IV was released people started complaining that the game was crashing or acting weird because the test part of the code, the dev mode area, had been deleted. The response to these complaints? Put in a gallery unlocker and add a Power Fantasy mode so you always pass stat checks.
This meant the mod no longer provides any benefit except to generate new bugs.