Minecraft Forums

I just got a new computer with Windows 8.1 on it. I was using the Yogscast Complete mod pack on my old computer that had windows 7. it was working just fine. now it won't open and I get this error message at the end

"2015-03-14 10:06:18 [SEVERE] [ForgeModLoader] Unable to launch
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.remove(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)"

I have the most up to date Java and Forge 956 for this mod pack as well as a source file for minecraft 1.6.4 for the forge to take something from. on my old computer i had java 7 but for some reason windows 8.1 gives me an error message every time I try to download java 7 which is supposed to be compatible. should I be able to use java 8 or is that why my minecraft keeps crashing. if I can't use java 8 does anyone know how to fix the java 7 issues? it tells me there is no installation pack.

Thanks

is that the one where you delete the META.NIF file? cause I tried that and it didn't work

no need to be condescending. I made a back up of the file before I deleted it. and believe me I have tried goggling for over two days now as well as talking to Microsoft to make sure it isn't a feature in windows 8.1. at this point I have restored everything to vanilla. I have removed and readded Minecraft, java and my ATLauncher. multiple times so that they are all back to standard.

thank you for the file.
P.s. just because someone is asking for help doesn't make them an idiot.