That is because you created a world with the same name a previously deleted world. Known as world corruption/biome replacement/chunk error. Delete the save folder, and then re-create the world.
Oh I see, I did just delete a world I forgot to change to superflat.
Spawned in a forest, with hills. Thought Maybe I hit the wrong world type.
Went to find a flat area to screenshot some item textures I made, and I found this.
So, is that one of the map options that I may have accidentaly hit, or is this a bug?
Makes for an interesting flatworld though.
And is this the right section for this? I haven't posted on here in a while.
Coming soon: Nintendo World Resource Pack
Oh I see, I did just delete a world I forgot to change to superflat.
Okay, thanks!
Coming soon: Nintendo World Resource Pack