: Temporarily disable your antivirus software. Some antivirus programs can interfere with game files, causing them to become corrupted or preventing them from running.
The game has evolved significantly since its "Undisputed 1" early days. Current versions now include: undisputed 1 download repack fix
Without more details on "Undisputed 1," here are general steps to potentially fix or enhance your download: : Temporarily disable your antivirus software