The sce_module fix is required for games that use additional libraries (.suprx files) which the program/game relies on. Vitamin, to my knowledge, fails to dump these suprx files in most (if not all?) dumps it performs, leaving some games in an unplayable state unless one adds in the missing (and decrypted) suprx library files to the "sce_module" folder.
You can find this fix on many sites that are already distributing Vita games/backups; and you may even already find them in those said Vita backups for you to use and fix on other games that may not immediately work after dumping.