When attempting to create a new world in ATM7 0.4.34, the game crashes with the following error:

java.lang.IllegalStateException: Feature order cycle found, involved biomes: [Reference{ResourceKey[minecraft:worldgen/biome / byg:basalt_barrera]=net.minecraft.world.level.biome.Biome@53cf9c8}]

The following two crash reports are related to this issue:
crash-2022-10-30_00.00.04-server.txt
crash-2022-10-29_19.24.40-client.txt

As far as I can tell, the crash can very likely be reproduced with the following steps:

1. Start an instance of the mod pack.
2. Click "Singleplayer".
3. Click "Create New World".
4. Click "Datapacks".
5. Click "Done".
6. Wait until "Validating selected data packs" is finished.
7. Click "Create New World".
8. "Preparing for world creation" will show for a couple minutes.
9. Once the chunk generation starts, the game may crash very early into that process with the above error.

The above mentioned exception also triggered for me:

crash-2022-11-06_09.02.41-server.txt

Triggered in Singleplayer as well as on the server by enabling lost cities.
I primarily played with the following defaultconfig:
lostcities-server.toml.txt

custom lost cities configs also don't seem to get saved to that toml file in singleplayer and seem make the problem worse (increase the chance to trigger it).

The error randomly occurs either when creating a world or after wandering around (and I guess triggering some kind of impossible generation scenario).

Closing as I think this was just a one-off error.

Try updating or replacing world generation modifying mods if this issue persists.