Minecraft Forums

I wanted to change up my game a bit from normal vanilla, so I went searching for some different mods to add. However, when I click play on the launcher, the "Game Output" screen comes up and the game doesn't launch. I'm not sure what the error is, so I would greatly appreciate some help with figuring this out. Thanks!

-If you need more information than this, let me know and I'll try to add it.

Current Mods:

Backpacks Mod

Enchanting Plus

MCA (Minecraft Comes Alive)

Mineralogy

More materials mod

Mr. Crayfish Furniture Mod

NotEnoughItems

Optifine

RadixCore (for MCA, I think)

Xaeros Minimap

Inventory Tweaks

Fast Leave Decay

Vein Miner

Forge client

Game Output Message:

[17:26:16] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[17:26:16] [main/INFO] [LaunchWrapper]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[17:26:16] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLTweaker
[17:26:16] [main/INFO] [FML]: Forge Mod Loader version 8.99.124.1450 for Minecraft 1.8 loading
[17:26:16] [main/INFO] [FML]: Java is Java HotSpot(TM) Client VM, version 1.8.0_45, running on Windows 7:x86:6.1, installed at C:\Program Files (x86)\Java\jre1.8.0_45
[17:26:17] [main/WARN] [FML]: The coremod lumien.fastleavedecay.asm.LoadingPlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[17:26:17] [main/WARN] [FML]: The coremod invtweaks.forge.asm.FMLPlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[17:26:17] [main/WARN] [FML]: The coremod codechicken.nei.asm.NEICorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[17:26:17] [main/INFO] [FML]: Loading tweaker optifine.OptiFineForgeTweaker from OptiFine_1.8.0_HD_U_D5.jar
[17:26:17] [main/WARN] [FML]: The coremod portablejim.veinminer.asm.VeinMinerCorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[17:26:17] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[17:26:17] [main/INFO] [LaunchWrapper]: Loading tweak class name optifine.OptiFineForgeTweaker
[17:26:17] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[17:26:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[17:26:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[17:26:17] [main/INFO] [LaunchWrapper]: Calling tweak class optifine.OptiFineForgeTweaker
[17:26:17] [main/INFO] [STDOUT]: [optifine.OptiFineForgeTweaker:dbg:49]: OptiFineForgeTweaker: acceptOptions
[17:26:17] [main/INFO] [STDOUT]: [optifine.OptiFineForgeTweaker:dbg:49]: OptiFineForgeTweaker: injectIntoClassLoader
[17:26:17] [main/INFO] [STDOUT]: [optifine.OptiFineClassTransformer:dbg:179]: OptiFine ClassTransformer
[17:26:17] [main/INFO] [STDOUT]: [optifine.OptiFineClassTransformer:dbg:179]: OptiFine URL: file:/C:/Users/Rachel/AppData/Roaming/.minecraft/mods/OptiFine_1.8.0_HD_U_D5.jar
[17:26:17] [main/INFO] [STDOUT]: [optifine.OptiFineClassTransformer:dbg:179]: OptiFine ZIP file: [email protected]
[17:26:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[17:26:23] [main/INFO] [FML]: Found valid fingerprint for Minecraft Forge. Certificate fingerprint e3c3d50c7c986df74c645c0ac54639741c90a557
[17:26:23] [main/INFO] [FML]: Found valid fingerprint for Minecraft. Certificate fingerprint cd99959656f753dc28d863b46769f7f8fbaefcfc
[17:26:23] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[17:26:23] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[17:26:23] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[17:26:23] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
Exception in thread "main" [17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: java.lang.NoClassDefFoundError: codechicken/core/launch/CodeChickenCorePlugin
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at codechicken.nei.asm.NEICorePlugin.getASMTransformerClass(NEICorePlugin.java:18)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper.injectIntoClassLoader(CoreModManager.java:115)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at net.minecraft.launchwrapper.Launch.launch(Launch.java:115)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: Caused by: java.lang.ClassNotFoundException: codechicken.core.launch.CodeChickenCorePlugin
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at java.lang.ClassLoader.loadClass(Unknown Source)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at java.lang.ClassLoader.loadClass(Unknown Source)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: ... 4 more
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: Caused by: java.lang.NullPointerException
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
[17:26:23] [main/INFO] [STDERR]: [java.lang.Throwable$WrappedPrintStream:println:-1]: ... 6 more

Install CodeChickenCore. And next time, please read the mod instructions.