I run a server for my friend group and have recently encountered a few crashes that seem to originate from this mod. The mod pack is Medieval MC (Link to server pack). Plus a few extra mods we decided to add.

I am attaching the two most recent crash logs which are a result of a mob/structure from this mod.
Crash description (same for both files): Accessing LegacyRandomSource from multiple threads
Line 160 of crash1.txt: "Description: ResourceKey[minecraft:worldgen/structure / greekfantasy:cyclops_cave]"
Line 160 of crash2.txt: "Description: ResourceKey[minecraft:worldgen/structure / greekfantasy:ocean_village]"

I will most likely disable the mod for now if it continues to crash, but I figured it may be helpful to report it here anyways.

Thanks!
crash1.txt
crash2.txt

Thanks for the detailed info and crash reports. I'll upload a fix soon.

Thanks for the detailed info and crash reports. I'll upload a fix soon.

No worries! If you need any more info about my specific environment I will be happy to provide anything, just let me know.

Please try Greek Fantasy 19.2.6 and let me know if the crash continues.