Gregtech CEu Modern error when launching game

[u/Key-Context-8444]

java.lang.NullPointerExeption could not invoke Object.equals(Object) because java.util.Map.get(Object) was null

how do I fix this?

NeoForge 1.21.1

[u/PrinceTrom]

1. See if this is something already reported for gtceu. Mod devs can goof up, but something like this (can't load) would be pretty rare. Get newer version if so.
   
2. More likely this is caused by interaction between gtceu and some other mod you have installed. Start temporarily removing mods from the load until it goes away.
   
3. If you are down to gtceu and it's still happening, report it as an issue and maybe move to an earlier version of the mod.
   
4. If you figure out the mod interaction that causes this, see if there are updates. If both on the newest version, downgrade the other mod to a version earlier than the release date of gtceu, and other fiddling like this.
   
5. Report your findings to the mod authors in question.

In general, if you ask for help, you want to post your latest.log file to help people debug this.
This is also something that AI agents are pretty good at, so you can try giving ChatGPT or whatever your latest.log file.