Do not just grab an old "ClothBrush3.max" file from a forum. Ensure you have the PolyCloth 207 Build for 2016–2025. The installer should contain: Downloading and Installing:
5
Version 2.0.7 represents the most stable iteration for modern workflows, supporting versions from 3ds Max 2016 all the way through 3ds Max 2025. Why PolyCloth? Physics vs. Traditional Sculpting