Item description:

There are two events in the game that do not properly account for the possibility that Gau is on the Veldt. One of those events is the party selection at Zozo after getting the first Magicite, and the other is the return to Zozo after the Magitek Research Facility caper. The anomaly with the first event means that your remaining party members will not go to Narshe, meaning you cannot swap out with them until you have the airship; however, the second anomaly prevents this from happening because after the Esper World flashback, one of your party members will be positioned where Terra is supposed to get off the bed, meaning the game cannot advance. This patch corrects both events.