But there was something else. A flashing icon in the top right corner. It wasn't the usual 'New Season' icon. It was a warning triangle.

: Some newer Nvidia drivers (e.g., version 565.90) have caused stability regressions that require specific profile flags or shader cache clears to resolve.

Restore from your backup and attempt the patching process again. If the problem persists, consider using the official update method instead.

Here is a full changelog for the Forza Horizon 5 update 1.508.298.0: