I downloaded the development kit for Minecraft 1.16.5 and launched it in IntelliJ IDEA.It seems this mixin not matches the mappings：

[12:22:43] [main/FATAL] [mixin/]: Mixin apply failed cgm.mixins.json:common.LivingEntityMixin -> net.minecraft.entity.LivingEntity: org.spongepowered.asm.mixin.injection.throwables.InvalidInjectionException Critical injection failure: @Inject annotation on capture could not find any targets matching 'attackEntityFrom' in net.minecraft.entity.LivingEntity. No refMap loaded. [PREINJECT Applicator Phase -> cgm.mixins.json:common.LivingEntityMixin -> Prepare Injections -> -> handler$zzp000$capture(Lnet/minecraft/util/DamageSource;FLorg/spongepowered/asm/mixin/injection/callback/CallbackInfoReturnable;)V -> Parse]
org.spongepowered.asm.mixin.injection.throwables.InvalidInjectionException: Critical injection failure: @Inject annotation on capture could not find any targets matching 'attackEntityFrom' in net.minecraft.entity.LivingEntity. No refMap loaded. [PREINJECT Applicator Phase -> cgm.mixins.json:common.LivingEntityMixin -> Prepare Injections -> -> handler$zzp000$capture(Lnet/minecraft/util/DamageSource;FLorg/spongepowered/asm/mixin/injection/callback/CallbackInfoReturnable;)V -> Parse]
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.validateTargets(InjectionInfo.java:656) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.findTargets(InjectionInfo.java:587) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.readAnnotation(InjectionInfo.java:330) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.(InjectionInfo.java:316) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.(InjectionInfo.java:308) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.CallbackInjectionInfo.(CallbackInjectionInfo.java:46) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_202] {}
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:1.8.0_202] {}
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_202] {}
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_202] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo$InjectorEntry.create(InjectionInfo.java:149) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.parse(InjectionInfo.java:708) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.prepareInjections(MixinTargetContext.java:1311) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.prepareInjections(MixinApplicatorStandard.java:1042) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:393) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:325) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.TargetClassContext.apply(TargetClassContext.java:383) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:365) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:250) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.service.modlauncher.MixinTransformationHandler.processClass(MixinTransformationHandler.java:131) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at org.spongepowered.asm.launch.MixinLaunchPluginLegacy.processClass(MixinLaunchPluginLegacy.java:131) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
at cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClassWithFlags(ILaunchPluginService.java:154) ~[modlauncher-8.1.3.jar:8.1.3+8.1.3+main-8.1.x.c94d18ec] {}
at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85) ~[modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120) ~[modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:265) ~[modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:136) ~[modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98) ~[modlauncher-8.1.3.jar:?] {}
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_202] {}
at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.8.0_202] {}
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[?:1.8.0_202] {}
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:138) ~[modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98) ~[modlauncher-8.1.3.jar:?] {}
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_202] {}
at net.minecraft.client.main.Main.main(Main.java:118) ~[forge-1.16.5-36.2.34_mapped_official_1.16.5-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_202] {}
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_202] {}
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_202] {}
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_202] {}
at net.minecraftforge.userdev.FMLUserdevClientLaunchProvider.lambda$launchService$0(FMLUserdevClientLaunchProvider.java:52) ~[forge-1.16.5-36.2.34_mapped_official_1.16.5-recomp.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.1.3.jar:?] {}
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.1.3.jar:?] {}
at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:108) [forge-1.16.5-36.2.34_mapped_official_1.16.5-recomp.jar:?] {}