Forge 36.2.0
Repurposed Structures 3.0.4

Other mods are installed, if you're having trouble reproducing the issue I can provide a full mod list.

Crash Log: https://gist.github.com/Febilian/b6331e2791319c8ae27016c422cb950f
Full Server Log: https://gist.github.com/Febilian/4da74f2791bcea994f3586081f2fb8bb

A player tested the same world in single player and reproduced the same crash with Blame installed. Here you go, their latest.log:

https://gist.github.com/Febilian/46e7769bd9ea55c49bf2a23ed9d13a33

can you put on the mod called Blame, start up the world, and then give me the latest.log file?
https://www.curseforge.com/minecraft/mc-mods/blame

The crash you have is when the start pool for a structure is nuked to be empty. This tends to happen when a mod adds a property unsafely to vanilla blocks which then break the parsing of my structure processor. Minecraft takes that error and nukes the pool files which leads to that crash

Ah you are using the RS Environmental Datapack that is broken and causes Flower Forests to crash because it forgot to have block properties stated for some of the processors. I made a PR to fix the datapack but you can download the fixed version from here while you wait: https://gitlab.com/pm065/RepurposedRepurposedStructures/-/merge_requests/1#note_645821914

I'm gonna leave up this issue report for others to see until my PR is merged and the REFORM modpack releases with the fixed datapack.

Fixed datapack to use:
RS_Abnormals_+_Farmers_Delight_Compat_Fixed.zip

Oh, we are indeed - that would explain things. I'll use the fixed one, thanks!

fixed, REFORM has been updated, thank you for your help, you can close the issue now.

Closing this issue report now as it turns out that pm095 archived their datapack repo and stopped working on the datapacks. So I downloaded their datapacks and now host them on my repo here: https://github.com/TelepathicGrunt/RepurposedStructures/releases

The Environmental changes pm095 did in one datapack is now merged into my Repurposed_Structures-Environmental datapack. The other two datapacks are Repurposed_Structures-Buzzier_Bees and Repurposed_Structures-Farmers_Delight which are now listed separately

I did fixed the issue with the environmental portion from pm095 that was the cause of this bug report so these datapacks I host myself should be safe and will be maintained by me going forward instead of being abandoned.