I have had the same problem...when hosting my own server (online with only one player allowed) and when I enter the new gorge biome the server crashes and the following message pops up 'Lost connection to server'. This doesn't make sense since my pc is running the server and connecting at the same time....this only happens with this mod, so my theory is that it is conflicting with one of my other mods.
UPDATE: I have sorted through all my mods and even when all of them are turned off the mod still crashes my server when I enter the biome. The new 'Reap What you Sow' Update may have broke the mod.