This is a common issue in many users. The data (savegames & user music) of GTA IV and EFLC is the same:
*C:\Users\sahdgsadf\My documents\Rockstar Games\GTAIV*
And it gives problems to me. Because after playing GTA IV, when I wanna play TBoGT, the loading screen is the same than GTA IV (with Niko and his story's characters), and finishing the load, the game crashes.
I need to fix that (the user data paths). If u know how to, please. Help me