When prompted for the installation path, keep it short. Avoid deep subfolders. C:\Dassault Systemes\B21 is recommended.
Don’t just double-click the setup file; follow this specific sequence to avoid registry errors: install catia v5 r21 on windows 11 fixed
Set it to and check Disable full-screen optimizations . Phase 4: Environment Variables (The Licensing Fix) When prompted for the installation path, keep it short