Ez miért van Minecraftban (1.7.2)?

Modos 1.7.2-n játszok,körülbelül 20 mod van telepítve.Ezidáig jól működött minden,de mikor el akarom indítani a játékot,vár néhány másodpercet,majd ezt írja ki:

[17:56:14] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[17:56:14] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker

[17:56:14] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker

[17:56:14] [main/INFO] [FML]: Forge Mod Loader version 7.2.211.1121 for Minecraft 1.7.2 loading

[17:56:15] [main/INFO] [FML]: Java is Java HotSpot(TM) Client VM, version 1.8.0_31, running on Windows 8:x86:6.2, installed at C:\Program Files (x86)\Java\jre1.8.0_31

[17:56:15] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[17:56:15] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker

[17:56:15] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker

[17:56:15] [main/ERROR] [LaunchWrapper]: Unable to launch

java.util.ConcurrentModificationException

at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_31]

at java.util.ArrayList$Itr.remove(Unknown Source) ~[?:1.8.0_31]

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(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release.

A forge verzióm:1.7.2-Forge10.12.2.1121(bár akármelyikkel csinálom,ugyanezt írja ki,verziótól függetlenül)Esetleg vki tapasztalt már hasonlót?Előre is köszi a válaszokat!