While using ID's Dragonform, if you use RB+X or RB+Y, there's a 50/50 chance to crash the game, not only for you, but for anyone using GBFR in the party.
It happens very frequently when fighting Proto Bahamut in the quest : The Tale of Bahamut's Rage. Only when casting RB+X or RB+Y while in ID's Dragonform.
While using ID's Dragonform, if you use RB+X or RB+Y, there's a 50/50 chance to crash the game, not only for you, but for anyone using GBFR in the party.
GBFR version : 1.6.1 Granblue version : 1.3.2