Mixin failures

Mixin Transformation of net.minecraft.client.main.Main Failed

What the log looks like

java\.lang\.RuntimeException: Mixin transformation of net\.minecraft\.client\.main\.Main failed

How to fix it

  1. Open latest.log or the launcher crash output and look at the Caused by lines below Mixin transformation of net.minecraft.client.main.Main failed to identify the real error.
  2. If the Caused by line says Mixin [...] from mod [<mod_name>] FAILED during PREPARE, remove that mod from your mods folder or replace it with a build made for your exact Minecraft version (e.g., do not use a 1.18.1 mod on 1.18.2).
  3. If the Caused by line shows NoSuchMethodError: net.fabricmc.loader.api.metadata.ModMetadata.getCustomElement at com.chocohead.mm.Plugin, an old mod using Manningham Mills (usually OptiFabric for 1.14.4–1.16.5) is incompatible with modern Fabric Loader; update OptiFabric (or use an updated fork), replace OptiFine/OptiFabric with Sodium, or downgrade Fabric Loader to 0.11.7.
  4. Restart Minecraft and check the log again in case another outdated mod triggers a new Caused by error.
LoadersFabric
SeverityStops the game
CategoryMixin failures

Check your own log

Related errors

Mixin failuresCritical injection failure — a mixin could not find its targetTwo mods are usually fighting over the same game methodMixin failuresInvalidMixinException: Mod Mixin Failed to ApplyOpen your latest.log or crash report and look for 'Mixin apply for mod' or the 'Config :' line inside the 'InvMixin failuresInvalidMixinException: Unexpecteded ClassMetadataNotFoundExceptionFind the line saying 'Mixin apply for mod <modname> failed' or 'from mod <modname>' right above the error in yMixin failuresMixin apply failed — one mod could not patch the gameThe line names the mixin config, and its prefix is the mod id that brokeMixin failuresMixinExtras is missing or too oldUpdate the mod that needs it — modern mods bundle MixinExtras themselvesMixin failuresMixinTargetAlreadyLoadedException: Required Class Loaded PrematurelyRename your SpongeForge JAR file in the mods folder so it begins with an underscore or 'aaa' (for example, '_s