Disable NZXT CAM, MSI Afterburner, and Razer Cortex, as these can conflict with Call of Duty: Modern Warfare. Shader Preloading. Shader Preloading is an important part of the first boot process. You're warned in-game to let the Shader Preloading process complete before starting any game mode. Fix 1: Switch out of your game, then switch back in. This is the first thing you should try when you have a black screen issue on Call of Duty Modern Warfare. To do this: -When your game is running, press the Alt and Tab keys on your keyboard at the same time to switch out of the game. -Press the Alt and Tab keys on your keyboard at the same time to switch back into your game.