First it is ok to start up Plitch before launching into your game, However Do Not Activate Prepare! Or Any Cheats until you have launched into the game via manual save or continue!

Once your game has fully loaded in, hit the pause button Alt Tab to Plitch activate prepare and then the cheats you wish to use Alt Tab back to game and have fun!

Before you close you game, Pause your game and Alt Tab to Plitch Turn Off Cheats and then Deactivate Prepare! Alt Tab back to your game,  Now  save your game and Close it down.   This should stop crashes and corrupted saves!