I had a bit of a glitch where the egg from Desert Festival (dragon) showed up as my Fairy when hatching. I don't think this is related to the upcoming error, however. I had just finished the Moth P quest conditions (hide&seek) and was on my way up to turn in the quest. I decided to camp which caused my game to crash with the following message box. Thinking that I could maybe bypass it, I tried to turn in the quest, but entering the bar would cause this same crash.