Minecraft Version

minecraft Version 1.21.6

Iris Version

R 1.9.0+1.21.6-fabric Iris 1.9.0 for Fabric 1.21.6

Sodium Version

sodium-fabric-0.6.13+mc1.21.6

Operating System

windows 11

What is your GPU?

nvidia rtx 3050 and 3060

Java Version

1.21.6

Reproduction Steps

1. Place a Redstone Lamp in front of a Redstone Repeater
2. Use a Lever to activate the Redstone Repeater
3. Game Crashes

Crash Report file and latest.log

---- Minecraft Crash Report ----
// My bad.

Time: 2025-06-17 22:37:56
Description: Unexpected error

java.lang.AssertionError: Can't.
at knot//net.minecraft.class_1921.iris$getRenderTarget(class_1921.java:851)
at knot//net.irisshaders.iris.layer.OuterWrappedRenderType.iris$getRenderTarget(OuterWrappedRenderType.java:88)
at knot//net.irisshaders.batchedentityrendering.impl.FullyBufferedMultiBufferSource.method_22993(FullyBufferedMultiBufferSource.java:161)
at knot//net.minecraft.class_761.handler$bec000$iris$batchedentityrendering$beginTranslucents(class_761.java:1585)
at knot//net.minecraft.class_761.method_62214(class_761.java:664)
at knot//net.minecraft.class_9909.method_61910(class_9909.java:67)
at knot//net.minecraft.class_761.method_22710(class_761.java:544)
at knot//net.minecraft.class_757.method_3188(class_757.java:738)
at knot//net.minecraft.class_757.method_3192(class_757.java:506)
at knot//net.minecraft.class_310.method_1523(class_310.java:1361)
at knot//net.minecraft.class_310.method_1514(class_310.java:947)
at knot//net.minecraft.client.main.Main.main(Main.java:265)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:480)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)

A detailed walkthrough of the error, its code path and all known details is as follows:

Additional context

No response

I get a crash when I try to play multiplayer using Essencial.
It works fine if I'm alone, and the shaders work fine too, but as soon as I open the world and the other person connects, it crashes for me.

@sourdemon Exactly the same thing happens to me, and it's because of the iris, because you remove the mod and everything works properly

just stop using essential, use e4mc or worldhost instead. essential is a super bloated mod with microtransactions & way too many unnecessary features to be compatible with anything.

you can host a server on your own PC very easily via ServerPackCreator

@chorbintime just stop using essential, use e4mc or worldhost instead. essential is a super bloated mod with microtransactions & way too many unnecessary features to be compatible with anything.

you can host a server on your own PC very easily via ServerPackCreator

Thanks for your alternatives, but I don't think it has anything to do with the fact that it has microtransactions, and the "just stop using essential" solution doesn't seem like a valid answer to me. It used to work fine, Iris rushed it out for 1.21.6 but didn't have time to fix this and other reported bugs.

@chorbintime just stop using essential, use e4mc or worldhost instead. essential is a super bloated mod with microtransactions & way too many unnecessary features to be compatible with anything.
you can host a server on your own PC very easily via ServerPackCreator

Thanks for your alternatives, but I don't think it has anything to do with the fact that it has microtransactions, and the "just stop using essential" solution doesn't seem like a valid answer to me. It used to work fine, Iris rushed it out for 1.21.6 but didn't have time to fix this and other reported bugs.

It has everything to do with the microtransactions - the developers dont care about their mod being stable and just want to milk their users for money.

There's no use case for Essential when much better alternatives exist. Just remove it.