The "CODEX" designation indicates this is a standalone update package for the PC version of the game. Based on community guides , the installation process typically involves:
For creators, the update was vital for maintaining clean save files: WWE.2K18.Update.v1.07-CODEX
: Restored full functionality for the host in private matches and addressed an issue on Xbox One (and mirrored in the PC update) where users were unable to join lobbies if they signed out of an active profile while in-game. The "CODEX" designation indicates this is a standalone