Can't figure out what causes it, if I disable the "Adventure" settings in this mod it does not crash anymore, so something with Looting is making issues or maybe another mod.

Minecraft 1.19.2
Forge: 43.2.8
Latest version of Apotheosis on 1.19.2

Crashlog:

crash-2023-04-15_10.34.57-server.txt

Reproduce the crash with 4 mods, which is caused by wrong datapack.
It seems you override the datapack with a version that dosn't define "common" rarity "helmet" in the affixes namespace.
Here is the crash-reports, I suggest you check the datapack you are loading, or delete it use the default datapack.

crash-2023-04-16_05.34.34-client.txt

This crash means you disabled enough affixes that there are none available for a particular rarity/category combo. You are responsible for not breaking your environment.