A mod crashed on startup!
net.fabricmc.loader.impl.FormattedException: java.lang.RuntimeException: Could not execute entrypoint stage 'preLaunch' due to errors, provided by 'advanced_runtime_resource_pack'!
at net.fabricmc.loader.impl.launch.knot.Knot.init(Knot.java:164)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:68)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
Caused by: java.lang.RuntimeException: Could not execute entrypoint stage 'preLaunch' due to errors, provided by 'advanced_runtime_resource_pack'!
at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.lambda$invoke0$0(EntrypointUtils.java:51)
at net.fabricmc.loader.impl.util.ExceptionUtil.gatherExceptions(ExceptionUtil.java:33)
at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.invoke0(EntrypointUtils.java:49)
at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.invoke(EntrypointUtils.java:35)
at net.fabricmc.loader.impl.launch.knot.Knot.init(Knot.java:162)
... 2 more
Caused by: net.fabricmc.loader.api.EntrypointException: Exception while loading entries for entrypoint 'preLaunch' provided by 'advanced_runtime_resource_pack'
at net.fabricmc.loader.impl.entrypoint.EntrypointContainerImpl.getEntrypoint(EntrypointContainerImpl.java:56)
at net.fabricmc.loader.impl.entrypoint.EntrypointUtils.invoke0(EntrypointUtils.java:47)
... 4 more
Caused by: java.lang.RuntimeException: Mixin transformation of net.devtech.arrp.ARRP failed
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:418)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:322)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:218)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:145)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:467)
at net.fabricmc.loader.impl.util.DefaultLanguageAdapter.create(DefaultLanguageAdapter.java:50)
at net.fabricmc.loader.impl.entrypoint.EntrypointStorage$NewEntry.getOrCreate(EntrypointStorage.java:117)
at net.fabricmc.loader.impl.entrypoint.EntrypointContainerImpl.getEntrypoint(EntrypointContainerImpl.java:53)
... 5 more
Caused by: org.spongepowered.asm.mixin.throwables.MixinApplyError: Mixin [mixins.mm.json:net.minecraft.class_1814 from mod mm] from phase [DEFAULT] in config [mixins.mm.json] FAILED during PREPARE
at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinError(MixinProcessor.java:638)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinPrepareError(MixinProcessor.java:585)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.prepareConfigs(MixinProcessor.java:570)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.select(MixinProcessor.java:462)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.checkSelect(MixinProcessor.java:438)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:290)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:234)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:202)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:413)
... 14 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTargetAlreadyLoadedException: Critical problem: mixins.mm.json:net.minecraft.class_1814 from mod mm target net.minecraft.class_1814 was loaded too early.
at org.spongepowered.asm.mixin.transformer.MixinInfo.readDeclaredTargets(MixinInfo.java:948)
at org.spongepowered.asm.mixin.transformer.MixinInfo.(MixinInfo.java:882)
at org.spongepowered.asm.mixin.transformer.MixinConfig.prepareMixins(MixinConfig.java:852)
at org.spongepowered.asm.mixin.transformer.MixinConfig.postInitialise(MixinConfig.java:797)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.prepareConfigs(MixinProcessor.java:568)
... 20 more

Not a fabric issue.

You have a mod using Mannigham Mills (mm) to hack something, but this is failing with an error about trying to bytecode modify an already loaded class, something that is not allowed:

Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTargetAlreadyLoadedException: Critical problem:
mixins.mm.json:net.minecraft.class_1814 from mod mm target net.minecraft.class_1814 was loaded too early.

There is not enough information in the error you posted to determine which mod is causing the problem, but I can tell you that class_1814 is the item Rarity class, that mainly just determines in what colour tool tips appear :-)
It is probably a mod that adds a new rarity to this enum?

I suggest you post a link to your full logs/latest.log in the discussions tab or discord.
But its likely you will have to experiment with removing mods to locate the problem one.
mm has little support for debugging problems.
https://github.com/Chocohead/Fabric-ASM#readme

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