The dragon eye quest event that spawns a free rider compound put it on top of an impassable wall. It was not able to be entered, the walls can be destroyed with raise land/lower land but not the tile with the compound. (walls from one of the titan event areas)
I have also had issues with any save file that I have gotten either the legendary armors or weapons from a quest. It seems to make the save file un-loadable. (the arena and the elemental temple quests)
