I turned my hardcore world into spectator after I was needing to take a picture for a sketch, but I left accidentally before I was able to go back to survival, and ever since then, my world gets stuck on "loading terrain" and I can't open it anymore. All of my other worlds work perfectly fine. I tried everything and have even backed up the world and reloaded it. Still nothing. It happens in other hardcore worlds too. 

1. have a hardcore world
2. turn to survival
3. turn to spectator
4. leave world while in spectator
5. try to join back

The worlds that I tried this in no longer work. I want to specify that i can’t get into the world, it isn’t a chunk loading issue. I cannot get into the world to set it to true