Batman: Arkham City Cheats
There is different versions and hosts of Batman: AC out there.
etc, all use varying types of .exe files.
So make sure you have the right version installed. Right click the games .exe file and goto properties and then the details tab to find out the version installed. Or check the main menu of the game see if a revision number is shown there.
Then match up that version and type of Batman:AC you have with the trainers available. I have used one about a month ago and it worked fine.
I.e. If on a disc you bought get Retail, if you downloaded the game via Steam or online stores then use the Steam version.
[Edited by DABhand, 7/23/2012 2:26:09 AM]
It is possible the first download got corrupted somehow.