This is what happens when you install Advent Of Ascension, and activate a Biomes O' Plenty world.
(Notice infinite ocean. This seed was awful.)
(Oh, and world settings are not custom. This really happens with O' Plenty and AOA. Proof is because I am on 1.7.10 as shown by F3 menu.)
"I don't know, just write something down for me, I don't care."