This file or folder is commonly found in the directory structure of compressed software installers (such as those from FitGirl or similar repackers). It generally contains files or binary data that can be excluded to save disk space if the user does not intend to use online/multiplayer features. Best Practices for Management
What to do:
Option A: How to Manage and Optimize the fgoptionalmpfilesbin Directory for Better Performance fgoptionalmpfilesbin better