Playing MCC on my dual-monitor PC, and I usually listen to music or have a show playing on my second monitor during matches. For the past week now, whenever I Alt+Tab out of game to interact with my second monitor, the game window will disappear and there is no way for me to pull it back up. I still hear the gameplay audio, and there have been three times now it has occurred while in a matchmaking game. This bug is forcing me to task manager exit and restart the game, resulting in a temporary ban on matchmaking. Plus, when this issue occurs and I attempt to close the game through Steam, the button to exit will not work and a popup message will occur saying “Halo: MCC has encountered a fatal error” …super frustrating!!!
Have you tried the suggestion in the existing alt+tab thread?
Edit: search term to use: ‘ALT+TAB CAUSING GAME TO DISAPPEAR, NOT CRASH’