I have had this problem for several months and I have no idea how to fix it. One day my friends and I decided we would try to create our own mods. We used Eclipse and the moment it started up we realized we had no idea what we were doing. We closed the program and do not believe we edited anything, but from that point forward I was never able to load up my modded profile again. I have tried different versions of forge, loading up the profile without my mods folder in case I was running to many mods, and even deleting my .minecraft and re-downloading entirely. I play in 1.7.2 . Once "play" is selected this is the game output:
[15:02:53] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [FML]: Forge Mod Loader version 7.2.217.1147 for Minecraft 1.7.2 loading
[15:02:54] [main/INFO] [FML]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_20, running on Windows 8.1:amd64:6.3, installed at C:\Program Files\Java\jre1.8.0_20
[15:02:54] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:02:54] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
[15:02:54] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:02:54] [main/ERROR] [LaunchWrapper]: Unable to launch
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_20]
at java.util.ArrayList$Itr.remove(Unknown Source) ~[?: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:?]
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
I have no idea what this means, and any assistance in this problem would be greatly appreciated.
[15:02:53] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker
[15:02:53] [main/INFO] [FML]: Forge Mod Loader version 7.2.217.1147 for Minecraft 1.7.2 loading
[15:02:54] [main/INFO] [FML]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_20, running on Windows 8.1:amd64:6.3, installed at C:\Program Files\Java\jre1.8.0_20
[15:02:54] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:02:54] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
[15:02:54] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:02:54] [main/ERROR] [LaunchWrapper]: Unable to launch
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_20]
at java.util.ArrayList$Itr.remove(Unknown Source) ~[?: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:?]
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
I have no idea what this means, and any assistance in this problem would be greatly appreciated.
Thanks, TheGoldnEagle