Eclipse cannot launch forge 1.6.4

[LordMucaus]

I've been trying to learn how to mod for minecraft, so I watched a tutorial on how to do so while following exact instructions. I get to the end of the tutorial, and I go to launch the mod for the first time (in eclipse, should have mentioned), and I get the following error as it refuses to launch forge:

 

Sep 10, 2014 1:09:49 PM net.minecraft.launchwrapper.LogWrapper log

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

Sep 10, 2014 1:09:49 PM net.minecraft.launchwrapper.LogWrapper log

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

Sep 10, 2014 1:09:49 PM net.minecraft.launchwrapper.LogWrapper log

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

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Forge Mod Loader version 6.4.45.953 for Minecraft 1.6.4 loading

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Java is Java HotSpot 64-Bit Server VM, version 1.8.0_20, running on Windows 7:amd64:6.1, installed at C:\Program Files\Java\jre1.8.0_20

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Managed to load a deobfuscated Minecraft name- we are in a deobfuscated environment. Skipping runtime deobfuscation

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

2014-09-10 13:09:49 [iNFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

2014-09-10 13:09:49 [sEVERE] [ForgeModLoader] Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(Unknown Source)

at java.util.ArrayList$Itr.remove(Unknown Source)

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

 

If I could get a fix for this issue, that would be great, and thank you in advance

[LexManos]

Update to the 'new' branch on our downloads page. It'll get moved to master here soon.