He's using SMB mode. So I guess he have a NTFS formated drive, so no need at all to split ISO, whatever size they have (could even be DVD9).
Of course you can still use ul format too if you really want (or if you are still using FAT32 ...).
So his problem is for sure individual access rights on files or bad filename (the extension must be ".iso", and the game_code in prefix should correspond to what is in the system.cnf in the ISO).
It's too late to think that we can worship human emotions
Because we've already evolved into machines in our minds