You must "sign" the new save with your unique Xbox User ID (XUID) . You can find this hex code by entering your gamertag on sites like XboxID Lookup. Run Swapper Tool: Open the Save Swapper tool as an administrator. Load the downloaded 100% save file. Paste your XUID hex code into the tool and click Export . Replace Original File: Delete your original save file in the wgs folder. Paste the newly exported file into that same folder.
: Tools like the Forza Save Swapper or Doliman’s Crypto Tool allow you to open a downloaded 100% save and inject your XUID into it so the game recognizes it as yours . forza horizon 5 100 save game microsoft store link