I was making a mod pack and had this coming up any idea how to fix it ?

 

crash log:

 

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-0.8.4.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-8.0.9.jar:8.0.9+86+master.3cf110c] {}
    at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85) ~[modlauncher-8.0.9.jar:?] {}
    at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120) ~[modlauncher-8.0.9.jar:?] {}
    at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:265) ~[modlauncher-8.0.9.jar:?] {}
    at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:136) ~[modlauncher-8.0.9.jar:?] {re:classloading}
    at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98) ~[modlauncher-8.0.9.jar:?] {re:classloading}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_51] {}
    at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:225) ~[?:?] {re:mixin,re:classloading,pl:mixin:APP:lightoverlay-forge.mixins.json:MixinClientConnection,pl:mixin:A}
    at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:134) ~[?:?] {re:classloading}
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:865) ~[?:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) ~[?:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
    at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:78) ~[?:?] {re:classloading,pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) [?:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
    at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) [?:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:A}
    at net.minecraft.server.MinecraftServer$$Lambda$24559/448792781.run(Unknown Source) [?:?] {}
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51] {}
Caused by: org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure: Constant modifier method getKeepAlivePacketInterval(J)J in randompatches.mixins.json:timeouts.ServerPlayNetHandlerKeepAliveMixin failed injection check, (0/1) succeeded. Scanned 1 target(s). Using refmap randompatches.refmap.json
    at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.postInject(InjectionInfo.java:468) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
    at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1362) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
    at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1051) ~[mixin-0.8.4.jar:0.8.4+Jenkins-b308.git-2accda5000f7602229606b39437565542cc6fba4] {}
    at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:400) ~[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] {}
    ... 19 more

Error in RandomPatches, make sure the mod is up to date.
if you already use the latest version of the mod, report the bug to tht mod author