reach_entity_attributes causes server crash due to Mixin InvalidMixinException on Mohist 1.20.1

[sunjood]

Minecraft Version : 1.20.1

Mohist Version : 1.20.1-016b9f50
(Forge 47.4.13, NeoForge 47.1.106)

Operating System : Windows x64

Logs :
https://mclo.gs/XXXXXXX
(Contains full startup log and runtime crash stacktrace)

Mod list :

• reach_entity_attributes
• Quark 4.0-462
• fogoverrides

Plugin list :

• ProtocolLib
• (other Bukkit plugins, not related to the crash)

Description of issue :

The server crashes at runtime with a FATAL error caused by a Mixin failure from the mod reach_entity_attributes.

Main error:
Mixin apply for mod reach_entity_attributes failed
@shadow field f_143670_ was not located in the target class
net.minecraft.server.network.ServerGamePacketListenerImpl$1

This leads to:

java.lang.NoClassDefFoundError:
net/minecraft/server/network/ServerGamePacketListenerImpl$1

The crash does NOT happen immediately at startup, but when the class
ServerGamePacketListenerImpl$1 is first accessed (for example when a player joins or executes a command, triggering command suggestion packets).

Environment details:

• Minecraft 1.20.1
• Mohist 1.20.1-016b9f50
• Forge 47.4.13 / NeoForge 47.1.106
• Mixin 0.8.5

Additional notes:

• Removing reach_entity_attributes completely resolves the crash.
• This appears to be a Mixin / mapping incompatibility with Mohist (SRG / Mojmap), especially targeting an anonymous inner class.
• Another warning also appears:

Unknown message ID: fogoverrides:c2s_handshake

but this does not crash the server and seems unrelated.

Please let me know if this is a known limitation regarding Fabric-oriented mods or Mixins targeting anonymous inner classes on Mohist.
Thank you for maintaining Mohist.

[glowingstone124]

It seems that you are trying to use a fabric mod in forge environment. Some inconsistencies are expected. You may try a forge implemention and see if this problem persists.