Try this.
Uninstall the game, move the save folder to another location.
Restart your PC to make sure to clean up anything in the memory.
Install the game.
After that, put on the 2nd disc (DLC). You must wait it for autorun, or hold the SHIFT key to stop autorun and do it manually. Anyway, you must be patient! Just run it one time!
After minutes of waiting, install the DLC.
Are you sure you dont have the ini. I'm pretty sure you should have the ini