FF6Tools - Browser-Based ROM Editor

My guess is that FF6Tools is unable to parse the event script properly because some bytes are invalid. That could cause bugs when you save. Also, when reopening a ROM make sure you always use the json file from when you last saved.

When you load the ROM in FF6Tools, does the event script in the vicinity of CC/0C05 match a vanilla ROM? What other event script edits have you made? Just the floating island dialog, or others? Do any of the patches you applied affect the event script? If you are able, try to check for differences between the event script in your modified ROM vs. a vanilla ROM.