"Portable" versions of professional software like CATIA V5 R21 are usually unofficial, repackaged versions designed to run without a standard installation. While they offer convenience for quick viewing or light editing on different machines, they come with significant risks.
Based on user discussions (e.g., on CAD forums, torrent descriptions, or portable app collections), the portable Catia V5 R21 is said to include: Portable Catia V5 R21
Frequent crashes can occur if the virtualized environment containing the portable files conflicts with the host system's DLLs. Licensing and Security: "Portable" versions of professional software like CATIA V5