Well when i click Play i will get this in the console (Forge 1.6.4)
Feb 07, 2015 10:59:17 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
Feb 07, 2015 10:59:17 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker
Feb 07, 2015 10:59:17 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker
2015-02-07 22:59:18 [iNFO] [ForgeModLoader] Forge Mod Loader version 6.4.49.965 for Minecraft 1.6.4 loading
2015-02-07 22:59:18 [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
2015-02-07 22:59:18 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
2015-02-07 22:59:18 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
2015-02-07 22:59:18 [iNFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
2015-02-07 22:59:18 [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
i dont know why it doesnt to it with any other forge i delted it re-dwonloaded it i chaged from latest and recommended still i got this please halp! if you want to msg me easier just sktpe me live:exavius