So.. I have just updated my server to 1.6.1, a previous 1.5.2 world. We had a worldborder set at around 2500 blocks, I have now removed it for my members to search the world for horses (simply because horses do not spawn in old generated biomes and beyond 2500 new generated biomes will appear). However, here's the problem: in these 'new' biomes that are generated, no mobs spawn at all. Only monsters (zombies, spiders, etc.) spawn, but no sheep, pigs, cows, horses or anything of that nature. Is this a Bukkit bug or is something going wrong? Also at newly generated areas? Done that command, does nothing. Bump.. anyone? EDIT by Moderator: merged posts, please use the edit button instead of double posting.
I both have those set already, besides.. if I didn't have mobs wouldn't spawn in the already generated areas..
Tinkerballs I think he meant /gamerule doMobSpawning true though if you have hostile mobs spawning, this should already be set to true and not be the issue. Horses, donkeys etc will spawn in chunks generated by 1.5 (and lower), though their spawn rate should be a little lower. If passive mobs are spawning normally everywhere else besides the newly generated chunks, I'd chalk it up to either a plugin is conflicting here, or your world was corrupted. did you try creating a new world and see how the spawning works?
Tinkerballs Just made a post about this here http://forums.bukkit.org/threads/horse-spawning-issue.157457/