[15:26:38] [Server thread/WARN] [FML]: MrTJPCore loaded a new chunk [13, 8] in dimension 0 (overworld) while populating chunk [15, 5], causing cascading worldgen lag.
[15:26:38] [Server thread/WARN] [FML]: Please report this to the mod's issue tracker. This log can be disabled in the Forge config.

Minecraft 1.12.2
Forge 14.23.5.2847
Ram - 8Gb
Relevant mods - All project red Mods.
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[21:10:41] [Server thread/WARN] [FML]: MrTJPCore loaded a new chunk [-73, -53] in dimension 0 (overworld) while populating chunk [-72, -53], causing cascading worldgen lag.
The same happened to my server.
Only difference: Forge 14.23.5.2854