If you need to manually restore a backup from your game files:
Rename them by removing the timestamp to match the original naming format (e.g., BAK1Save0x0.sgd Restart the game to load the restored checkpoint. Steam Community Downloading a "Riddler-Free" Save File batman arkham knight riddler trophies save file fix
This is the most searched solution. If you are on or Epic Games , you have the most power to fix this. You do not need to restart the entire game. If you need to manually restore a backup