Whenever I install my new profile "Forge", I try to launch my game with my Minecraft account. But Minecraft just will not launch! I use the 1.6.4 Forge installer and it creates the profile, but just never launches. Plzzzz help!!!! :'(

The console log is there for a reason. We need it.

I have the same problem. I have tried everything but always when i try to launch minecraft with forge 1.7.2 it closes the launcher but minecraft wont launch. It just closes. And here is my log:

 

 

[18:52:39] [main/INFO]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[18:52:39] [main/INFO]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[18:52:39] [main/INFO]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker

[18:52:39] [main/INFO]: Forge Mod Loader version 7.2.59.999 for Minecraft 1.7.2 loading

[18:52:39] [main/INFO]: Java is Java HotSpot 64-Bit Server VM, version 1.8.0_20, running on Windows 8.1:amd64:6.3, installed at C:\Program Files\Java\jre1.8.0_20

[18:52:39] [main/INFO]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[18:52:39] [main/INFO]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

[18:52:39] [main/INFO]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[18:52:39] [main/ERROR]: Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_20]

at java.util.ArrayList$Itr.remove(Unknown Source) ~[?:1.8.0_20]

at net.minecraft.launchwrapper.Launch.launch(Launch.java:117) [launchwrapper-1.9.jar:?]

at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]

 

Please help!!! 

So i installed it many times before but now it is not letting me launch it. when i went to my minecraft launcher it said the everything right but when i clicked play it never open up to the menu.Please help me figure out whats wrong.