Describe the bug
NullPointerException in random places but always related to ItemList
Unsure what exactly causes this issue, but AE crashes the server every hour or so.
Notable about my setup is that it uses AE2 fluid crafting and my plethora fork to automatically craft items.

To Reproduce
Did not find a way to reproduce on demand.

Expected behavior
No crash.

Additional context
A few crash reports with different stack traces:
crash-2023-04-02_08.52.37-server.txt
crash-2023-04-02_09.33.37-server.txt
crash-2023-04-02_10.31.21-server.txt

Environment

• Minecraft Version: 1.12.2
• AE2 Version: rv6-stable-7-extended_life-v0.55.10
• AE2FC Version: 2.4.16-r
• Forge Version: 14.23.5.2860

I decreaced how often i auto-request craftings to have a minimum delay of 1s between and since then it has not crashed again

I figured it out.
Plethora submits jobs in the ICraftingCallback which is in fact not on the main thread