can not get forge 9.11.1.965 to go past the launcher

[wisp4400]

so ive been trying and failing to get minecraft to start up with forge 9.11.1.965 installed. whenever i attempt to launch minecraft the launcher will load but as soon as you hit play it just closes and minecraft doesnt open. ive done it using the installer and have tried using the universal. Ive completly uninstalled it and reinstalled it. i downgraded java to java 7. none of these things seem to help.

this is the game output

 

Dec 23, 2014 11:21:22 AM net.minecraft.launchwrapper.LogWrapper log

INFO: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker

Dec 23, 2014 11:21:22 AM net.minecraft.launchwrapper.LogWrapper log

INFO: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker

Dec 23, 2014 11:21:22 AM net.minecraft.launchwrapper.LogWrapper log

INFO: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker

2014-12-23 11:21:22 [iNFO] [ForgeModLoader] Forge Mod Loader version 6.4.49.965 for Minecraft 1.6.4 loading

2014-12-23 11:21:22 [iNFO] [ForgeModLoader] 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

2014-12-23 11:21:22 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-12-23 11:21:22 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

2014-12-23 11:21:22 [iNFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-12-23 11:21:22 [sEVERE] [ForgeModLoader] Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)

at java.util.ArrayList$Itr.remove(ArrayList.java:865)

at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)

at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

Java HotSpot 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release

 

 

and this is the log file ...i think

 

2014-12-22 21:37:25 [iNFO] [ForgeModLoader] Forge Mod Loader version 6.4.49.965 for Minecraft 1.6.4 loading

2014-12-22 21:37:25 [iNFO] [ForgeModLoader] 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

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Java classpath at launch is C:\Users\Reid\AppData\Roaming\.minecraft\libraries\net\minecraftforge\minecraftforge\9.11.1.965\minecraftforge-9.11.1.965.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\net\minecraft\launchwrapper\1.8\launchwrapper-1.8.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\ow2\asm\asm-all\4.1\asm-all-4.1.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-library\2.10.2\scala-library-2.10.2.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-compiler\2.10.2\scala-compiler-2.10.2.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\lzma\lzma\0.0.1\lzma-0.0.1.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\argo\argo\2.25_fixed\argo-2.25_fixed.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\bouncycastle\bcprov-jdk15on\1.47\bcprov-jdk15on-1.47.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\google\guava\guava\14.0\guava-14.0.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\com\google\code\gson\gson\2.2.2\gson-2.2.2.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\Reid\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\Reid\AppData\Roaming\.minecraft\versions\1.6.4-Forge9.11.1.965\1.6.4-Forge9.11.1.965.jar

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Java library path at launch is C:\Users\Reid\AppData\Roaming\.minecraft\versions\1.6.4-Forge9.11.1.965\1.6.4-Forge9.11.1.965-natives-80612912970273

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Enabling runtime deobfuscation

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Instantiating coremod class FMLCorePlugin

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Enqueued coremod FMLCorePlugin

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Instantiating coremod class FMLForgePlugin

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Enqueued coremod FMLForgePlugin

2014-12-22 21:37:25 [FINE] [ForgeModLoader] All fundamental core mods are successfully located

2014-12-22 21:37:25 [FINE] [ForgeModLoader] Discovering coremods

2014-12-22 21:37:25 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-12-22 21:37:25 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

2014-12-22 21:37:25 [iNFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-12-22 21:37:25 [sEVERE] [ForgeModLoader] Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)

at java.util.ArrayList$Itr.remove(ArrayList.java:865)

at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)

at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

 

 

 

so if anyone has an idea of whats wrong i would really appreciate a fix for it

[wisp4400]

ok 1) why not and 2) i need it for the mods i want to use. so why am i not supposed to use it?