[BUG] World crashes when attempting to enter the Deeper Down

[JayMeyer-Materials]

Describe the bug
When I try to enter the Deeper Down, I have a few seconds before the world starts to lag heavily and then Minecraft crashes. Based on the logs, i think it has something to do with the shader that Spectrum tries to force on me when I enter the dimension. The error code when the game crashes suggests I need to update my graphics driver, but I already tried that and it still crashes. I have been able to enter the dimension on an older version of spectrum before.

To Reproduce
Enter Deeper Down. Wait until world lags.

Expected behavior
Being able to enter the dimension and play.

Version information
Spectrum Version: 1.10.5
Minecraft Version: 1.21.1
Mod Loader: Fabric

Crash Report
https://mclo.gs/lma5Ann
https://mclo.gs/upCj6PL

[DaFuqs]

I assume the crash goes away if you disable the shaders in the mod config?

Your modlist is very long. Got any mods in mind that might mess with shader loading?

[JayMeyer-Materials]

I assume the crash goes away if you disable the shaders in the mod config?

Your modlist is very long. Got any mods in mind that might mess with shader loading?

That worked! I hadn't even considered messing with the mod config, so thanks for reminding me that that was a thing I could do.

And I don't think so? I've never had this problem before with shaderpacks that I've downloaded, but I admit that I haven't tried turning on shaders in this instance.

[SubordinalBlue]

I've got a player submitted report of same.

Craftoria, but latest version of the pack, so not outdated Spectrum
(sorry that took so long, btw).

Currently working with the player to sort out what other mods may be involved, but the error stack trace looks like just iris... which I wouldn't have expected. (was a red herring, the bit about Iris—see next post)

The player does not have shaders (the global, Iris kind) on... they don't use them.

The didn't have a crash-report, just logs:

https://gnomebot.dev/paste/mclogs/Acm4AJ1

[24952](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24952)    [25May2026 22:39:49.881] [Render thread/INFO] [com.mojang.blaze3d.platform.GlDebug/]: OpenGL debug message: id=385, source=SHADER COMPILER, type=ERROR, severity=HIGH, message='0:1(10): error: GLSL 4.40 is not supported. Supported versions are: 1.10, 1.20, 1.30, 1.40, 1.50, 3.30, 4.00, 4.10, 4.20, 1.00 ES, and 3.00 ES'
[24953](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24953)    [25May2026 22:39:49.883] [Render thread/ERROR] [Spectrum/]: Failed to load post-process shader [spectrum:shaders/post/dd_color_grading.json]
[24954](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24954)    [25May2026 22:39:49.883] [Render thread/ERROR] [Spectrum/]: 
[24955](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24955)    net.irisshaders.iris.helpers.FakeChainedJsonException: Invalid shaders/program/highlights.json (mod/spectrum): 
[24956](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24956)    	at net.minecraft.server.ChainedJsonException.handler$zij000$iris$changeShaderParseException:L516
[24957](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24957)    	at TRANSFORMER/minecraft@1.21.1/net.minecraft.server.ChainedJsonException.forException(ChainedJsonException.java) ~[client-1.21.1-20240808.144430-srg.jar%23679!/:?]
[24958](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24958)    	at net.minecraft.client.renderer.EffectInstance.<init>:L139
[24959](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24959)    	at net.minecraft.client.renderer.PostPass.<init>:L32
[24960](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24960)    	at net.minecraft.client.renderer.PostChain.addPass:L282
[24961](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24961)    	at net.minecraft.client.renderer.PostChain.parsePassNode:L133
[24962](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24962)    	at net.minecraft.client.renderer.PostChain.load:L86
[24963](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24963)    	at net.minecraft.client.renderer.PostChain.<init>:L54
[24964](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24964)    	at de.dafuqs.spectrum.render.SpectrumShaders.loadPostProcess:L29
[24965](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24965)    	at de.dafuqs.spectrum.render.SpectrumShaders.updateShaders:L55
[24966](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24966)    	at de.dafuqs.spectrum.registries.client.SpectrumClientEventListeners.afterClientTick:L168
[24967](https://gnomebot.dev/paste/mclogs/Acm4AJ1#L24967)    	at net.neoforged.bus.EventBus.post:L360

[SubordinalBlue]

Second report for same player, but with Iris removed from their instance.

Stack trace not giving me a clue right now.

I should compare original issue opener's mod list with our... but they're on Fabric and Craftoria is on NeoForge.

https://gnomebot.dev/paste/mclogs/KV46oav

[SubordinalBlue]

Well, that was fun ^*...

Went to replicate by just tp'ing straight to the DD: was fine for a minute or so, then whole machine got wedged, memory slammed, and hard reboot.

I did have Iris in, and turned shaders on while in the DD.
Can try again without Iris, later today.

Latest log: https://mclo.gs/Sb2EsBL

Debug log, zipped as it's ~20MB uncompressed:

debug.log.zip