Before you start the first game (e.g. skirmish) of Granatball Reploded, hit the "Default" button in the game setup screen. If your game crashes then delete the Skirmish.ini from "%appdata%\Red Alert 3\Profiles\[YourProfile]".
Do the same thing when you play the original Red Alert 3 or another mod after playing Granatball Reploded!
This is necessary because of the way Red Alert 3 handles loading from and saving to the ini files.