The armor (chest plate) belonging to the player LucidLie has a enchantment on it, he will not say what the enchantment is but during the wizards tower event every time he is damaged all players in his vicinity are set on fire. This is actually more dangerous than the event and has taken the fun out of boss fights and events that he participates in for anyone not entirely fireproof.
I know what it has, if that would help. There's this one custom enchant, and the issue is actually pretty easy to solve. Just check boss times often and have a fire resistance potion/s ready. It's probably his best chest plate. Another way to fix is getting full scary gear because of the fire resistance effect it gives you. It's annoying, but the scary set is pretty decent regardless, so I wouldn't worry about it. So while it probably will cause inconveniences, there are many ways to solve this.
(Also, keeping a talisman of the firefighter (Slimefun) on you can be helpful anyways, so I would recommend that. it gives you fire resistance if you are afflicted by fire/lava)
Hope that helps! It's not a fix, but it should help.