If CATIA fails to start, verify your Environment file located in C:\ProgramData\DassaultSystemes\CATEnv . Ensure the paths for CATDLLPath and CATICPath correctly point to your installation directory. Windows 7 Compatibility mode enabled on Setup.exe . .NET Framework 3.5 enabled. Latest Service Pack applied. License folder manually created in ProgramData .
Fix 1: Java RuntimeCATIA R21 uses an older version of Java for its documentation and some UI elements. Download and install Java 8 (JRE) if the help files won't open. install+catia+v5+r21+on+windows+11+updated
Right-click the CATIA shortcut > > Compatibility > Change high DPI settings . If CATIA fails to start, verify your Environment