So I was trying to run minecraft forge 1.7.2 7.2.211..1121 and right as the play button started saying "loading" and then said "already playing" and the game output opened, it stop loading and the play button say "play" again! plz help me! here is the game output

[17:09:17] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[17:09:17] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[17:09:17] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker

[17:09:17] [main/INFO] [FML]: Forge Mod Loader version 7.2.211.1121 for Minecraft 1.7.2 loading

[17:09:17] [main/INFO] [FML]: Java is Java HotSpot 64-Bit Server VM, version 1.8.0_25, running on Windows 7:amd64:6.1, installed at C:\Users\Abram\Desktop\runtime\jre-x64\1.8.0_25

[17:09:17] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[17:09:17] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

[17:09:17] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[17:09:17] [main/ERROR] [LaunchWrapper]: Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_25]

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

 

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