Version:
1.20.1 Forge 47.3.29
CreativeCore 2.12.31
ItemPhysic 1.8.4
Chemlib 2.0.19

How it happens:
Throw any item to "gas block" of mod Chemlib, like hydrogen, of which the bucket is up-side-down, and game freezes. It is repeatable.

Strangely, I tried to fix it with datapack but failed. I don't understand why liquid blocks never trigger this issue.

datapack folder:
data\chemlib\elements.json, and ...\compounds.json

Viscosity value of gas without modification is 0, and that of liquid is 1000. Changing this(including density and matter state) with datapack doesn't work for no reason.

crash log:
java.lang.IllegalArgumentException: Start element (9223367638808264704) is larger than end element (-9223372036854775808)
at MC-BOOTSTRAP/[email protected]/it.unimi.dsi.fastutil.longs.LongAVLTreeSet$Subset.(LongAVLTreeSet.java:1080)
at MC-BOOTSTRAP/[email protected]/it.unimi.dsi.fastutil.longs.LongAVLTreeSet.subSet(LongAVLTreeSet.java:1047)
at TRANSFORMER/[email protected]/net.minecraft.world.level.entity.EntitySectionStorage.m_188362_(EntitySectionStorage.java:57)
at TRANSFORMER/[email protected]/net.minecraft.world.level.entity.EntitySectionStorage.m_261111_(EntitySectionStorage.java:122)
at TRANSFORMER/[email protected]/net.minecraft.world.level.entity.LevelEntityGetterAdapter.m_142232_(LevelEntityGetterAdapter.java:43)
at TRANSFORMER/[email protected]/net.minecraft.world.level.Level.m_6249_(Level.java:641)
at TRANSFORMER/[email protected]/net.minecraft.world.level.EntityGetter.m_183134_(EntityGetter.java:62)
at TRANSFORMER/[email protected]/net.minecraft.world.level.CommonLevelAccessor.m_183134_(CommonLevelAccessor.java:23)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.Entity.handler$enf000$ac_collide(Entity.java:20732)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.Entity.m_20272_(Entity.java)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.Entity.m_6478_(Entity.java:632)
at TRANSFORMER/[email protected]/net.minecraft.world.entity.item.ItemEntity.m_8119_(ItemEntity.java:138)
at TRANSFORMER/[email protected]/net.minecraft.server.level.ServerLevel.m_8647_(ServerLevel.java:694)
at TRANSFORMER/[email protected]/net.minecraft.world.level.Level.mixinextras$bridge$accept$146(Level.java)
at TRANSFORMER/[email protected]/com.bawnorton.neruina.handler.TickHandler.safelyTickEntities(TickHandler.java:92)
at TRANSFORMER/[email protected]/net.minecraft.world.level.Level.wrapOperation$bla000$catchTickingEntities$notTheCauseOfTickLag(Level.java:3540)
at TRANSFORMER/[email protected]/net.minecraft.world.level.Level.m_46653_(Level.java:479)
at TRANSFORMER/[email protected]/net.minecraft.server.level.ServerLevel.m_184063_(ServerLevel.java:343)
at TRANSFORMER/[email protected]/net.minecraft.world.level.entity.EntityTickList.m_156910_(EntityTickList.java:54)
at TRANSFORMER/[email protected]/net.minecraft.server.level.ServerLevel.m_8793_(ServerLevel.java:323)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_5703_(MinecraftServer.java:893)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_5705_(MinecraftServer.java:814)
at TRANSFORMER/[email protected]/net.minecraft.client.server.IntegratedServer.m_5705_(IntegratedServer.java:89)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:661)
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.m_206580_(MinecraftServer.java:251)
at java.base/java.lang.Thread.run(Thread.java:842)