Konami has provided new details regarding the recently discovered Metal Gear Solid V: The Phantom Pain save-corruption bug which occurs with the buddy Quiet. The publisher says it has identified the exact trigger for the bug, and will patch it soon, but for now, Konami has provided instructions for how to avoid it.
As stated previously, this bug, which affects all versions of the game, can be triggered in Episode 29 and Episode 42 when Quiet is used as a buddy. However, Konami now says you can still use Quiet during these missions and not run the risk of losing your save if you use the Butterfly as your emblem through the missions. Alternatively, you can complete the mission with another buddy, or avoid losing your save by not raising your Bond level with Quiet to Max. My advice, for Episode 29 at least, would be to use D-Walker.
“In the meantime, we apologize deeply for the problem and thank you for your continued patience as we work to resolve the issue,” Konami said.