Ok so I redid my computer and am redoing everything so it is a fresh copy of Minecraft

I load it up run 1.7.2 once everything loads fine. I then use the recommended build forge-1.7.2-10.12.2.1121-installer ( I have also tried latest forge-1.7.2-10.12.2.1147-installer) it downloads everything with no errors, so I launch Minecraft choose forge and make sure its using the right profile but when I hit launch never ever happens.

 

I was using java 8 but read it does not work with forge so I removed it and only have java 7 installed.

I have tried deleting .minecraft and starting over it does not work.

 

I'm on windows 8.1 64 bit

 

 

here is my fml-client-latest.log

 

I see the error [00:03:59] [main/ERROR] [LaunchWrapper/]: Unable to launch but not sure what that means.

 

 

[00:03:59] [main/INFO] [FML/]: Forge Mod Loader version 7.2.217.1147 for Minecraft 1.7.2 loading

[00:03:59] [main/INFO] [FML/]: Java is Java HotSpot Client VM, version 1.8.0_20, running on Windows 8.1:x86:6.3, installed at C:\Program Files (x86)\Java\jdk1.8.0_20\jre

[00:03:59] [main/DEBUG] [FML/]: Java classpath at launch is C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\minecraftforge\forge\1.7.2-10.12.2.1147\forge-1.7.2-10.12.2.1147.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\minecraft\launchwrapper\1.9\launchwrapper-1.9.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\ow2\asm\asm-all\4.1\asm-all-4.1.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-library\2.10.2\scala-library-2.10.2.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-compiler\2.10.2\scala-compiler-2.10.2.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\java3d\vecmath\1.3.1\vecmath-1.3.1.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\sf\trove4j\trove4j\3.0.3\trove4j-3.0.3.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\ibm\icu\icu4j-core-mojang\51.2\icu4j-core-mojang-51.2.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\lzma\lzma\0.0.1\lzma-0.0.1.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\io\netty\netty-all\4.0.10.Final\netty-all-4.0.10.Final.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\google\guava\guava\15.0\guava-15.0.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\google\code\gson\gson\2.2.4\gson-2.2.4.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\com\mojang\authlib\1.3\authlib-1.3.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\apache\logging\log4j\log4j-api\2.0-beta9\log4j-api-2.0-beta9.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\apache\logging\log4j\log4j-core\2.0-beta9\log4j-core-2.0-beta9.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\stephen\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\stephen\AppData\Roaming\.minecraft\versions\1.7.2-Forge10.12.2.1147\1.7.2-Forge10.12.2.1147.jar

[00:03:59] [main/DEBUG] [FML/]: Java library path at launch is C:\Users\stephen\AppData\Roaming\.minecraft\versions\1.7.2-Forge10.12.2.1147\1.7.2-Forge10.12.2.1147-natives-8741822403462

[00:03:59] [main/DEBUG] [FML/]: Enabling runtime deobfuscation

[00:03:59] [main/DEBUG] [FML/]: Instantiating coremod class FMLCorePlugin

[00:03:59] [main/DEBUG] [FML/]: Added access transformer class cpw.mods.fml.common.asm.transformers.AccessTransformer to enqueued access transformers

[00:03:59] [main/DEBUG] [FML/]: Enqueued coremod FMLCorePlugin

[00:03:59] [main/DEBUG] [FML/]: Instantiating coremod class FMLForgePlugin

[00:03:59] [main/DEBUG] [FML/]: Added access transformer class net.minecraftforge.transformers.ForgeAccessTransformer to enqueued access transformers

[00:03:59] [main/DEBUG] [FML/]: Enqueued coremod FMLForgePlugin

[00:03:59] [main/DEBUG] [FML/]: All fundamental core mods are successfully located

[00:03:59] [main/DEBUG] [FML/]: Discovering coremods

[00:03:59] [main/INFO] [LaunchWrapper/]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[00:03:59] [main/INFO] [LaunchWrapper/]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

[00:03:59] [main/INFO] [LaunchWrapper/]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[00:03:59] [main/ERROR] [LaunchWrapper/]: Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_20]

at java.util.ArrayList$Itr.remove(ArrayList.java:865) ~[?: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:?]

 

 

You have not removed Java 1.8, as the log states.

 

To resolve this, you must update to the latest version of Forge (10.13.1.1217). All Forge version can be found here.

 

There is already a solution to this posted on the EAQ, so please go check if your problem is listed there next time before starting a thread.