So, my forge client (I am using the Recommended version. 1.8.9) won't start. I am using the Antique Atlas mod for 1.8 and NEI 1.8.9 universal. And the error logs are as shown:
2016-03-09 16:07:17,371 WARN Unable to instantiate org.fusesource.jansi.WindowsAnsiOutputStream
2016-03-09 16:07:17,374 WARN Unable to instantiate org.fusesource.jansi.WindowsAnsiOutputStream
[16:07:17] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLTweaker
[16:07:17] [main/INFO] [FML]: Forge Mod Loader version 11.15.1.1722 for Minecraft 1.8.9 loading
[16:07:17] [main/INFO] [FML]: Java is Java HotSpot 64-Bit Server VM, version 1.8.0_25, running on Windows 8.1:amd64:6.3, installed at C:\Program Files (x86)\Minecraft\runtime\jre-x64\1.8.0_25
[16:07:17] [main/WARN] [FML]: The coremod codechicken.lib.asm.CCLCorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[16:07:17] [main/WARN] [FML]: The coremod codechicken.nei.asm.NEICorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[16:07:17] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[16:07:17] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[16:07:19] [main/INFO] [FML]: Found valid fingerprint for Minecraft. Certificate fingerprint cd99959656f753dc28d863b46769f7f8fbaefcfc
[16:07:19] [main/ERROR] [FML]: FML appears to be missing any signature data. This is not a good thing
[16:07:19] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[16:07:19] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
2016-03-09 16:07:19,578 WARN Unable to instantiate org.fusesource.jansi.WindowsAnsiOutputStream
2016-03-09 16:07:19,597 WARN Unable to instantiate org.fusesource.jansi.WindowsAnsiOutputStream
2016-03-09 16:07:19,598 WARN Unable to instantiate org.fusesource.jansi.WindowsAnsiOutputStream
[16:07:19] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
Exception in thread "main" [16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1052]: java.lang.NoClassDefFoundError: codechicken/core/launch/CodeChickenCorePlugin
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1052]: at codechicken.nei.asm.NEICorePlugin.getASMTransformerClass(NEICorePlugin.java:18)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1052]: at net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper.injectIntoClassLoader(CoreModManager.java:121)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1052]: at net.minecraft.launchwrapper.Launch.launch(Launch.java:115)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1052]: at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: Caused by: java.lang.ClassNotFoundException: codechicken.core.launch.CodeChickenCorePlugin
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: ... 4 more
[16:07:19] [main/INFO] [sTDERR]: [java.lang.Throwable:printStackTrace:643]: Caused by: java.lang.NullPointerException
[16:07:19] [main/INFO] [sTDERR]: [java.lang.Throwable:printStackTrace:643]: at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
[16:07:19] [main/INFO] [sTDERR]: [java.lang.Throwable:printStackTrace:643]: ... 6 more
After it says ...6 more the logs stop, and there's nothing else listed. The game never starts, the launcher disappears then immediately reappears. I've uninstalled both mods that I'm using, and the game starts, but with either of the mods (or any mod, as I've tried dozens) the game gives those exact same logs.