Install Catia V5 R21 On Windows 11 Fixed -

The primary compatibility issue with installing CATIA V5 R21 on Windows 11 is the software's age. CATIA V5 R21 was released in 2014, and it may not be fully compatible with the latest operating system. Moreover, Windows 11 has enhanced security features, such as Secure Boot and Windows Defender, which may prevent CATIA V5 R21 from installing or running properly.