Board Thread:Bug Reports/@comment-27516710-20160821232722/@comment-25101089-20160822003749

SamwiseFilmore wrote: It happened to me in Dale while I was traveling down a road. However, it also happened there while there wasn't a road in sight, same in gondor. However, it did seem to be worse with slabs being generated. I've never seen worldgen lag that bad in any of the 18+ versions of the mod I've played. And it doesn't happen in areas that have been already generated, although the only testing I did there was with areas generated before an update. I'll test with newly generated terrain.

Tbh, might be easier to troubleshoot on the chat.

Personally I think it's unlikely that it's related to slabs. It's more likely to be related to the large number of structures the game is trying to generate at once. But I'll see what happens when slab generation is disabled.