Board Thread:Bug Reports/@comment-94.29.101.245-20160421153442/@comment-27219153-20161031155316

5.55.80.63 wrote: Oh and by the way, the issue is not shown on Single Player worlds, so I actually believe there is a problem in your server. Yes, I would agree with that.

[03:34:54] [Server thread/WARN]: java.lang.RuntimeException: Could not load LOTR biome map image

This looks like it can't find the map that tells it what biomes to generate and where. If it can't find this, it just defaults to ocean. Maybe deleting and redownloading the mod would help?