Minecraft Version

1.21.1 (LTS)

Mod Loader

Fabric

Describe the Issue

When using a sophisticated backpack with crafting upgrade, game crashes. Am able to open other backpacks without the crafting upgrade.

Logs

2025-09-16-7.log

java.lang.IllegalAccessError: class net.p3pp3rf1y.sophisticatedcore.compat.craftingtweaks.CraftingUpgradeTweakUIPart tried to access protected method 'net.minecraft.client.gui.Element net.minecraft.client.gui.screen.ingame.HandledScreen.addDrawableChild(net.minecraft.client.gui.Element)' (net.p3pp3rf1y.sophisticatedcore.compat.craftingtweaks.CraftingUpgradeTweakUIPart and net.minecraft.client.gui.screen.ingame.HandledScreen are in unnamed module of loader 'knot' @6093dd95)

The crash seems to be happening inside of Sophisticated Core. Try updating to a more recent version, as this is likely already fixed.

java.lang.IllegalAccessError: class net.p3pp3rf1y.sophisticatedcore.compat.craftingtweaks.CraftingUpgradeTweakUIPart tried to access protected method 'net.minecraft.client.gui.Element net.minecraft.client.gui.screen.ingame.HandledScreen.addDrawableChild(net.minecraft.client.gui.Element)' (net.p3pp3rf1y.sophisticatedcore.compat.craftingtweaks.CraftingUpgradeTweakUIPart and net.minecraft.client.gui.screen.ingame.HandledScreen are in unnamed module of loader 'knot' @6093dd95)

The crash seems to be happening inside of Sophisticated Core. Try updating to a more recent version, as this is likely already fixed.

I updated all sophisticated mods. only thing that fixed it was removing craft tweaks.

Ah, I was looking at the official Sophisticated Core versions and thought it was outdated.

In that case, the issue still remains inside Sophisticated Core (Unofficial Fabric port), specifically due to its accesswidener seemingly not applying. No idea why, but I suggest reporting the issue to them instead.

The reason it only happens with Crafting Tweaks installed is because Sophisticated Backpacks only runs the crashing code when that's the case.

Ah, I was looking at the official Sophisticated Core versions and thought it was outdated.

In that case, the issue still remains inside Sophisticated Core (Unofficial Fabric port), specifically due to its accesswidener seemingly not applying. No idea why, but I suggest reporting the issue to them instead.

The reason it only happens with Crafting Tweaks installed is because Sophisticated Backpacks only runs the crashing code when that's the case.

I made a issue with both mods. To get the bug known. Thanks for your help

Little update from my side in case someone stumbles across this searching for a solution.

I found out that this crash happens due to Recipe Essentials.
I'm not entirely sure why yet but without it Sophisticated and Crafting Tweaks works fine together.