Konami has released a statement warning players of a potential bug that can corrupt their Metal Gear Solid 5: The Phantom Pain game saves rendering them unusable. Please be aware the that bug affects all platforms of the game.
Konami has apologized for the glitch and is working on a patch that will be released in the future. It seems that if you have Quiet come along as a buddy while playing “Mission 29” or “Mission 42” you could risk your game save file becoming corrupted, so you may want to avoid using her for said missions.