Hola, alguien que me pueda ayudar. Lanzo el minecraft 1.7.2 y sin problema. Instalo el forge para la version 1.7.2 descargado desde la página y al intentar usar la versión forge aparece esto en la consola de desarrollo:

Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker
Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker
Cliente> [11:12:28] [main/INFO] [FML]: Forge Mod Loader version 7.2.211.1121 for Minecraft 1.7.2 loading
Cliente> [11:12:28] [main/INFO] [FML]: Java is Java HotSpot(TM) Client VM, version 1.8.0_45, running on Windows 7:x86:6.1, installed at C:\Program Files\Java\jre1.8.0_45
Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
Cliente> [11:12:28] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
Cliente> [11:12:28] [main/ERROR] [LaunchWrapper]: Unable to launch
Cliente> java.util.ConcurrentModificationException
Cliente> at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_45]
Cliente> at java.util.ArrayList$Itr.remove(Unknown Source) ~[?:1.8.0_45]
Cliente> at net.minecraft.launchwrapper.Launch.launch(Launch.java:117) [launchwrapper-1.9.jar:?]
Cliente> at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]
El juego termino sin problemas detectados (exit code 0)
Borrando C:\Users\dell\AppData\Roaming\.minecraft\versions\1.7.2-Forge10.12.2.1121\1.7.2-Forge10.12.2.1121-natives-8203411454149

El caso es que nunca abre la pantalla del minecraft.

Alguien sabe lo que debo hacer? que es lo que está mal?

Gracias de antemano por su ayuda.