While this specific file name belongs to an unofficial distribution, the game has since received further official support and is currently in a much more stable state: Current Performance:
The most common way to add visual or gameplay features is through the AnvilToolkit , which allows you to unpack and edit the game's Visual Enhancements: Assassins.Creed.Unity.Update.v1.5.Proper-RELOADED Pc
However, if you have: