Stick to the official PreSonus site to ensure your hardware isn't bricked by faulty or malicious software.

If you must use a .rar file from a third-party site, scan it with an up-to-date antivirus before opening.

stijnwop/manureSystem: Manure System modification ... - GitHub

Official PreSonus firmware updates are streamlined through their UC Surface software , which automates the detection and installation process. If "ULT18.rar" is a Mod or Game Asset

Check community forums like GitHub or Steam Community hubs to see if other users have flagged the specific file for errors or compatibility issues. Final Recommendation

Official updates for the ULT series and related mixers are provided directly through the MyPreSonus portal. These official files are typically .zip or .img formats rather than .rar .