Minecraft Version

1.20.1

Mod Loader and Version

Forge 47.3.12-1.20.1

Ad Astra! Version

1.15.19

Addon Mod Version (This Mod)

6.15

The details

1. Got Fuel Loader
2. Placed Fuel loader near rockets
3. Server crashed
4. Cant join back untill took out the mod

Can't reproduce when Ad Astra and this mod only installed.
Please upload crashreport.

This is the output of my server:
latest.log

I'm in a similar situation, but I have Dandi2k8's Ad Extendra additionally installedhttps://modrinth.com/mod/ad_extendra-continuation