java.lang.IllegalStateException: Registry is already frozen (trying to add key ResourceKey[minecraft:loot_pool_entry_type / minecells:special_weapon])

[CuBr202]

Minecells version: 1.20.1 - 2.0.0
Runtime Environment: Forge + Sinytra Connector

I'm a modpack maker and 2 of my pack's players send me crash reports:
https://pastebin.com/vjpU8pVX
https://pastebin.com/iwrwG4ce

Their crash reason are all the same: java.lang.IllegalStateException: Registry is already frozen (trying to add key ResourceKey[minecraft:loot_pool_entry_type / minecells:special_weapon])

However, me and all other people started the modpack well(Everyone download from the same source, including the 2 crashed players, and started on Java 21).

Therefore, I consider this is a strange bug which happen on SOME people's computer. Please help me figure out why.