Melted MID-campaign? Like, your rogue token just slowly turned into a puddle while you were trying to sneak past a guard? That's a whole new level of game immersion, just not the good kind.
Oh, I see what happened. They didn't mean the actual game token melted. "Melted" is slang for when a player gets upset and quits the game right in the middle of a session. It's like they had a meltdown. So the campaign fell apart because a person left, not because a plastic mini got ruined. It's a real bummer when that happens.