Game crashs on joining a 1.20.1 server with ViaFabric

[FuckNullPointerException]

Steps to reproduce

1.join a server which version is lower than client (26.122.3.172:61160,in version 1.20.1)
2."Anti packer kick" module catched lot of exceptions
3.game crashed

Crash report key words:
java.lang.NullPointerException: Cannot invoke "net.minecraft.class_746.method_24828()" because "this.mc.field_1724" is null

mappings:
this.mc.field_1724 -> this.mc.player
method_24828() -> getY()
What a hell are you doing?a null check is difficult?
Link to full crash report
crash-2025-08-05_14.09.49-client.txt

Link to crash report/log (upload to https://mclo.gs and paste resulting link here)

uploaded

Meteor Version

1.21.7-Build_1

Minecraft Version

Minecraft 1.21.7 - Fabric

Operating System

Windows

Before submitting a crash report

• This crash wasn't already reported (I have searched crash reports on GitHub).

• This is a valid crash (I am able to reproduce this on the latest dev build).

[FuckNullPointerException]

what a fuck crash did you do?it kept from 1.20.4 , and no one fixed it until 1.21.7?

[crosby-moe]

code was written in a time when the player & world could not be null in that specific code path, changes in the minecraft source since then have made that assertion untrue

we could add a null check for this specific case and fix it right now rather than wait until we push a fix to the underlying issue, but you specifically are an annoying user, so closed as duplicate of underlying issue