This is an issue not a bug. I downloaded a map the 10 Years Of Minecraft in the marketplace content and then i loaded the world and everything was ok i guess then i used the Anniversary Golden Minecart and i ride it along way to the end but almost at the end the "Aquatic Update" Structure gone wrong it's like the water was flowing out of the aquarium or something i don't know but the water destroyed the rails so i discontinued and proceeded to the end. Please tell the creator to fix this map