The version of the crack. This implies that as the developers pushed out patches (like the Version 5.x updates), older crack iterations broke, requiring a "v5" update from scene groups or bypass uploaders to match the game's executable.
The target game. Propnight was a 4v1 physics-based prop hunt survival horror game developed by Fntastic.
If you legally own the game on Steam and are trying to fix crashing or file corruption issues, you should never use external .rar packages. Instead, use Steam's built-in secure utilities: