Cannot Load World With Odd Combination of Mods

[CraftyZombie]

What happened?

Minecraft 1.21.1
NeoForge 21.1.208

After installing the mods listed below, worlds will not load, immediately kicking the user with "Invalid Player Data".

Yes, I'm aware that the suspects are Unify and Oreganized, but it can't be reproduced without the others.

Logs: https://gist.github.com/CraftyZombie/2744fda74f3c830b1d68927657c5881b

Relevant log output

[Server thread/ERROR] [minecraft/ServerConfigurationPacketListenerImpl]: Couldn't place player in world
net.neoforged.fml.ModLoadingException: Loading errors encountered:
	- Oreganized (oreganized) encountered an error while dispatching the net.neoforged.neoforge.event.BuildCreativeModeTabContentsEvent event
	  java.lang.IllegalArgumentException: Itemstack 1 unify:lead_block already exists in the tab's list

[PssbleTrngle]

And this does not happen with unify and some other mod which also adds lead?

[CraftyZombie]

No, it does not. The issue mentions Oreganized, and before isolating it, I was using several other mods that add lead.

[PssbleTrngle]

Interesting, I do not quite know how unify works, I'll have to take a closer look at it next week

[CraftyZombie]

I've also reported to Unify now, but their support is through Discord, which is always less responsive.