On 1.20.4 this mod crashes with the error message:
java.lang.RuntimeException: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered at net.minecraftforge.fml.loading.BackgroundWaiter.runAndTick(BackgroundWaiter.java:30) ~[fmlloader-1.20.4-49.0.31.jar:49.0.31] {} at net.minecraft.client.main.Main.main(Main.java:156) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:runtimedistcleaner:A} at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] {} at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?] {} at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] {} at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?] {} at net.minecraftforge.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:91) ~[fmlloader-1.20.4-49.0.31.jar:?] {} at net.minecraftforge.fml.loading.targets.CommonLaunchHandler.lambda$makeService$0(CommonLaunchHandler.java:75) ~[fmlloader-1.20.4-49.0.31.jar:?] {} at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:74) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.Launcher.run(Launcher.java:114) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.Launcher.main(Launcher.java:73) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.BootstrapEntry.main(BootstrapEntry.java:17) ~[modlauncher-10.1.2.jar:?] {} at net.minecraftforge.bootstrap.Bootstrap.moduleMain(Bootstrap.java:97) ~[bootstrap-2.0.0.jar!/:?] {} at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] {} at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?] {} at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] {} at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?] {} at net.minecraftforge.bootstrap.Bootstrap.start(Bootstrap.java:48) ~[bootstrap-2.0.0.jar!/:?] {} at net.minecraftforge.bootstrap.ForgeBootstrap.main(ForgeBootstrap.java:18) ~[bootstrap-2.0.0.jar!/:?] {} Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:392) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:250) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.service.modlauncher.MixinTransformationHandler.processClass(MixinTransformationHandler.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.launch.MixinLaunchPluginLegacy.processClass(MixinLaunchPluginLegacy.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClassWithFlags(ILaunchPluginService.java:142) ~[modlauncher-10.1.2.jar:10.1.2] {} at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:91) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:107) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.TransformingClassLoader.maybeTransformClassBytes(TransformingClassLoader.java:44) ~[modlauncher-10.1.2.jar:?] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.readerToClass(SecureModuleClassLoader.java:473) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.findClass(SecureModuleClassLoader.java:399) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.loadClass(SecureModuleClassLoader.java:415) ~[securemodules-2.2.10.jar:2.2.10] {} at java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?] {} at net.minecraft.world.level.block.Blocks.<clinit>(Blocks.java:323) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:object_holder_definalize:A} at net.minecraft.world.level.block.FireBlock.m_53484_(FireBlock.java:307) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:accesstransformer:B} at net.minecraft.server.Bootstrap.m_135870_(Bootstrap.java:46) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading} at net.minecraft.client.main.Main.lambda$main$0(Main.java:156) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:runtimedistcleaner:A} at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[?:?] {} at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?] {} at java.lang.Thread.run(Thread.java:833) ~[?:?] {} Caused by: org.spongepowered.asm.mixin.throwables.MixinApplyError: Mixin [etched.mixins.json:JukeboxBlockEntityMixin] from phase [DEFAULT] in config [etched.mixins.json] FAILED during APPLY at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinError(MixinProcessor.java:636) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinApplyError(MixinProcessor.java:588) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:379) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:250) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.service.modlauncher.MixinTransformationHandler.processClass(MixinTransformationHandler.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.launch.MixinLaunchPluginLegacy.processClass(MixinLaunchPluginLegacy.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClassWithFlags(ILaunchPluginService.java:142) ~[modlauncher-10.1.2.jar:10.1.2] {} at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:91) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:107) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.TransformingClassLoader.maybeTransformClassBytes(TransformingClassLoader.java:44) ~[modlauncher-10.1.2.jar:?] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.readerToClass(SecureModuleClassLoader.java:473) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.findClass(SecureModuleClassLoader.java:399) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.loadClass(SecureModuleClassLoader.java:415) ~[securemodules-2.2.10.jar:2.2.10] {} at java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?] {} at net.minecraft.world.level.block.Blocks.<clinit>(Blocks.java:323) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:object_holder_definalize:A} at net.minecraft.world.level.block.FireBlock.m_53484_(FireBlock.java:307) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:accesstransformer:B} at net.minecraft.server.Bootstrap.m_135870_(Bootstrap.java:46) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading} at net.minecraft.client.main.Main.lambda$main$0(Main.java:156) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:runtimedistcleaner:A} at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[?:?] {} at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?] {} at java.lang.Thread.run(Thread.java:833) ~[?:?] {} Caused by: org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException: @Shadow field f_271436_ was not located in the target class net.minecraft.world.level.block.entity.JukeboxBlockEntity. Using refmap etched-refmap.json at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attachFields(MixinPreProcessorStandard.java:629) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attach(MixinPreProcessorStandard.java:305) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.createContextFor(MixinPreProcessorStandard.java:280) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinInfo.createContextFor(MixinInfo.java:1288) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:292) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.TargetClassContext.apply(TargetClassContext.java:383) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:365) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:250) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.service.modlauncher.MixinTransformationHandler.processClass(MixinTransformationHandler.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at org.spongepowered.asm.launch.MixinLaunchPluginLegacy.processClass(MixinLaunchPluginLegacy.java:131) ~[mixin-0.8.5.jar:0.8.5+Jenkins-b310.git-155314e6e91465dad727e621a569906a410cd6f4] {} at cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClassWithFlags(ILaunchPluginService.java:142) ~[modlauncher-10.1.2.jar:10.1.2] {} at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:91) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:107) ~[modlauncher-10.1.2.jar:?] {} at cpw.mods.modlauncher.TransformingClassLoader.maybeTransformClassBytes(TransformingClassLoader.java:44) ~[modlauncher-10.1.2.jar:?] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.readerToClass(SecureModuleClassLoader.java:473) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.findClass(SecureModuleClassLoader.java:399) ~[securemodules-2.2.10.jar:2.2.10] {} at net.minecraftforge.securemodules.SecureModuleClassLoader.loadClass(SecureModuleClassLoader.java:415) ~[securemodules-2.2.10.jar:2.2.10] {} at java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?] {} at net.minecraft.world.level.block.Blocks.<clinit>(Blocks.java:323) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:object_holder_definalize:A} at net.minecraft.world.level.block.FireBlock.m_53484_(FireBlock.java:307) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:accesstransformer:B} at net.minecraft.server.Bootstrap.m_135870_(Bootstrap.java:46) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading} at net.minecraft.client.main.Main.lambda$main$0(Main.java:156) ~[forge-1.20.4-49.0.31-client.jar:?] {re:classloading,pl:runtimedistcleaner:A} at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[?:?] {} at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?] {} at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?] {} at java.lang.Thread.run(Thread.java:833) ~[?:?] {}