Ok, the key changer itself works and it does change the key. I use dayz commander to launch DayZ and don't launch it with steam. If i launch it with my original key which is banned, it works fine, but i obviously can't get into servers with battleye. I have two extra working keys, but i get multiple errors when i try to load DayZ with them.
EDIT FIX:::::: If anyone else was having problems i have found a fix. All you need to do is uninstall British Armed Forces and Private Military. Now if you want them again, install with another program using the unbanned key
If you open DayZ to the main menu. Click on Expansions and make sure the appropriate ones are checked. I just disable the ones your allowed to. Doubt this is your actual issue. Just making an assumption based on the screenshot.
That does not work and i can't find anything to fix it