[19:26:25] [Server thread/WARN] [FML]: Recurrent Complex loaded a new chunk [11, 1] in dimension 7 (twilight_forest) while populating chunk [11, 0], causing cascading worldgen lag.
[19:26:25] [Server thread/WARN] [FML]: Please report this to the mod's issue tracker. This log can be disabled in the Forge config.

Duplicate of #155. I recommend pushing down the structureSpawnChance and / or tree decoration replacement chance down in the config for now. A fix will, hopefully, soon follow.

@Ivorforce thanks for the reply, how can we reduce tree decoration replacement chance?

It's an option in the config called baseWeight_tree

Ok thanks.