Store Top: Forza Horizon 5 100 Save Game Microsoft

Because the save file says you completed "Chapter 3 of the V10 story," but the game's internal flags haven't triggered the phone call from Alejandro to start Chapter 4, your character enters a soft lock. You have the achievement, but the mission won't appear. The game thinks you cheated, so it stops giving you new content.

"Save corrupted" message appears.