Hello
This is Sidney, an independent Microsoft expert, but also a customer just like you. I will try to help you resolve your issue.
You want to be able to play this game. However, the Forza servers are explicitely stating that your profile is invalid. Only direct solution would be to create a new account, but you would lose your save.
You can probably find more information by contacting them directly.
https://support.forzamotorsport.net/hc/en-us/re...
Best,
Sidney
Disclaimer: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.