I restarted my whole forge workspace (Typed the gradlew and all that crap) but when I began coding, I needed to test run, but only to find out

that the test run dosen't work. I have been searching for so long on how to fix it, but every method people put out dosen't work out for me.

So hopefully someone can help me here.

 

Console when trying to run:

[21:24:32] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[21:24:32] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[21:24:32] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker

[21:24:32] [main/INFO] [FML]: Forge Mod Loader version 7.2.211.1121 for Minecraft 1.7.2 loading

[21:24:32] [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\Java\jre1.8.0_25

[21:24:32] [main/INFO] [FML]: Managed to load a deobfuscated Minecraft name- we are in a deobfuscated environment. Skipping runtime deobfuscation

[21:24:32] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[21:24:32] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

[21:24:32] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[21:24:32] [main/ERROR] [LaunchWrapper]: Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_25]

at java.util.ArrayList$Itr.remove(Unknown Source) ~[?:1.8.0_25]

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:?]

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

 

And YES I am on 64-Bit I checked.

 

Screenshots:

http://gyazo.com/548461b7cda3d6d588b6b734d1f33c79

http://gyazo.com/22cda9786400dfa20bb04aa313cd64fe

http://gyazo.com/cab99c64ed45b0e7b3d60832c1880872

It looks like you're using Java 8. I do not think that is currently supported/recommended. Mojang is still targeting Java 6 I believe.

It looks like you're using Java 8. I do not think that is currently supported/recommended. Mojang is still targeting Java 6 I believe.

 

Or, you know, just read the EAQ...

Basically: Update your Minecraft and Forge.

I got it to work. I had JRE 8, so I uninstalled it, and got Jre7. Then I had another problem where it would say this: "no lwjgl in java.library.path" So I had to set the Native Location, then everything worked fine.