The latest version that got released 3 days ago makes it so that my modlist cant be played in multiplayer with my friend but reverting to a previous version fixes this. The latest version is still playable in single player which is why there is no crash list.
this here is the list of mods im using for private gameplay with a friend.
list of mods.txt

Which version of MC are you on?

using latest forge

sorry forgot to mention it is 1.16.4

could you send the server debug.log, even without a crash it will have useful info?

this it?
debug.log

Yes, thank you.

Can you tell me which mod adds zinc and bismuth?

should not be any mods adding that

From the log I can see that both bees have been loaded, so there must be something adding them. Did you search JEI?

hold on for me to check

nothing in jei other than productive bees items

wait thier is ex nihilo if i search deeper through recipes

weird that it is not in jei

still nothing on bismuth

nevermind also on ex nihilo if i search through centrifuge

Looks like they add both https://github.com/NovaMachina-Mods/ExNihiloSequentia/tree/1.16/src/main/resources/data/forge/tags/items/ingots

The trouble then is that there's no block when there is an ingot. I can make you a datapack which should fix it until I get a new version out.

thats cool

zinc_bismuth_datapack.zip

Throw this in the servers world/datapacks folder and enable. It will remove the need for zinc and bismuth blocks.
Let me know if it works!

thank you it seemed to have worked perfectly