First, please feel free to check out the AI answer already given out.
The error message you quoted ("The account you're attempting to sign in with isn't provisioned for this environment") is commonly related to the account being used to sign into Xbox services rather than the Far Cry 6 installation itself.
Could you clarify a couple of things?
- Are you signed into the Microsoft Store, Xbox app, and Windows with the same Microsoft account that purchased Far Cry 6?
- Did you purchase the game directly from the Microsoft Store, or was it redeemed from a code, Ubisoft promotion, or another retailer?
The answers to those questions will help determine whether this is an account provisioning/licensing issue or something specific to the Xbox sign-in services.
If the game is correctly associated with your account and the error persists, it may ultimately require Xbox Support to investigate the entitlement attached to the purchase.
Thank you for your time