Tekkit won't launch

[mps_devil]

I've downloaded tekkit, but when I try to launch it it does everything, the launcher closes and then a second later opens again with Minecraft never appearing. Here's the console log:

[b#283] Expected MD5: 94a9d4cbcb9ceaa25000fa303fa81acc Calculated MD5: 94a9d4cbcb9ceaa25000fa303fa81acc
[b#283] Expected MD5: b62087eb4b11746987c800c0512890ef Calculated MD5: b62087eb4b11746987c800c0512890ef
[b#283] OS: windows 8.1
[b#283] Identified as windows
[b#283] Starting download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm, with 3 tries remaining
[b#283] Starting download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm, with 3 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/417979e451a4ed37c22f5340a9c3cd4a?s=60&d=retro, with 3 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/4c9b9cd817e62d043070a821551c04f0?s=60&d=retro, with 3 tries remaining
[b#283] Download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm Failed!
[b#283] Starting download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm, with 2 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/2a29f323eddf3410fb1b531b10f7df6f?s=60&d=retro, with 3 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/07b1950664b5569324a88727516e761d?s=60&d=retro, with 3 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/07b1950664b5569324a88727516e761d?s=60&d=retro, with 3 tries remaining
[b#283] Starting download of http://www.gravatar.com/avatar/07b1950664b5569324a88727516e761d?s=60&d=retro, with 3 tries remaining
[b#283] Download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm Failed!
[b#283] Starting download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm, with 1 tries remaining
[b#283] Download of http://crafatar.com/avatars/2a02f1f36318457abef5eb9ecc537b30?size=100&helm Failed!
[b#283] Error downloading user face image: mps_devil
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining
[b#283] Running C:Program FilesJavajre1.8.0_31binjavaw.exe -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx6144m -XX:MaxPermSize=256m -Djava.library.path=C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinnatives -Dfml.core.libraries.mirror=http://mirror.technicpack.net/Technic/lib/fml/%s -Dminecraft.applet.TargetDirectory=C:UsersPeterAppDataRoaming.technicmodpackstekkitmain -Djava.net.preferIPv4Stack=true -cp C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinmodpack.jar;C:UsersPeterAppDataRoaming.techniccachenetminecraftlaunchwrapper1.8launchwrapper-1.8.jar;C:UsersPeterAppDataRoaming.techniccacheorgow2asmasm-all4.1asm-all-4.1.jar;C:UsersPeterAppDataRoaming.techniccacheorgscala-langscala-library2.10.2scala-library-2.10.2.jar;C:UsersPeterAppDataRoaming.techniccacheorgscala-langscala-compiler2.10.2scala-compiler-2.10.2.jar;C:UsersPeterAppDataRoaming.techniccachelzmalzma0.0.1lzma-0.0.1.jar;C:UsersPeterAppDataRoaming.techniccachenetsfjopt-simplejopt-simple4.5jopt-simple-4.5.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodecodecjorbis20101023codecjorbis-20101023.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodecodecwav20101023codecwav-20101023.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodelibraryjavasound20101123libraryjavasound-20101123.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodelibrarylwjglopenal20100824librarylwjglopenal-20100824.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodesoundsystem20120107soundsystem-20120107.jar;C:UsersPeterAppDataRoaming.techniccacheargoargo2.25_fixedargo-2.25_fixed.jar;C:UsersPeterAppDataRoaming.techniccacheorgbouncycastlebcprov-jdk15on1.47bcprov-jdk15on-1.47.jar;C:UsersPeterAppDataRoaming.techniccachecomgoogleguavaguava14.0guava-14.0.jar;C:UsersPeterAppDataRoaming.techniccacheorgapachecommonscommons-lang33.1commons-lang3-3.1.jar;C:UsersPeterAppDataRoaming.techniccachecommons-iocommons-io2.4commons-io-2.4.jar;C:UsersPeterAppDataRoaming.techniccachenetjavajinputjinput2.0.5jinput-2.0.5.jar;C:UsersPeterAppDataRoaming.techniccachenetjavajutilsjutils1.0.0jutils-1.0.0.jar;C:UsersPeterAppDataRoaming.techniccachecomgooglecodegsongson2.2.2gson-2.2.2.jar;C:UsersPeterAppDataRoaming.techniccacheorglwjgllwjgllwjgl2.9.0lwjgl-2.9.0.jar;C:UsersPeterAppDataRoaming.techniccacheorglwjgllwjgllwjgl_util2.9.0lwjgl_util-2.9.0.jar;C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinminecraft.jar net.minecraft.launchwrapper.Launch --username mps_devil --session token:8a86632b83c64e72b81853ea51cbf2cb:2a02f1f36318457abef5eb9ecc537b30 --version 1.6.4-Forge9.11.1.965 --gameDir C:UsersPeterAppDataRoaming.technicmodpackstekkitmain --assetsDir C:UsersPeterAppDataRoaming.technicassetsvirtuallegacy --tweakClass cpw.mods.fml.common.launcher.FMLTweaker --title Tekkit --icon C:UsersPeterAppDataRoaming.technicassetspackstekkitmainicon.png
[b#283] C:Program FilesJavajre1.8.0_31binjavaw.exe -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx6144m -XX:MaxPermSize=256m -Djava.library.path=C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinnatives -Dfml.core.libraries.mirror=http://mirror.technicpack.net/Technic/lib/fml/%s -Dminecraft.applet.TargetDirectory=C:UsersPeterAppDataRoaming.technicmodpackstekkitmain -Djava.net.preferIPv4Stack=true -cp C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinmodpack.jar;C:UsersPeterAppDataRoaming.techniccachenetminecraftlaunchwrapper1.8launchwrapper-1.8.jar;C:UsersPeterAppDataRoaming.techniccacheorgow2asmasm-all4.1asm-all-4.1.jar;C:UsersPeterAppDataRoaming.techniccacheorgscala-langscala-library2.10.2scala-library-2.10.2.jar;C:UsersPeterAppDataRoaming.techniccacheorgscala-langscala-compiler2.10.2scala-compiler-2.10.2.jar;C:UsersPeterAppDataRoaming.techniccachelzmalzma0.0.1lzma-0.0.1.jar;C:UsersPeterAppDataRoaming.techniccachenetsfjopt-simplejopt-simple4.5jopt-simple-4.5.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodecodecjorbis20101023codecjorbis-20101023.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodecodecwav20101023codecwav-20101023.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodelibraryjavasound20101123libraryjavasound-20101123.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodelibrarylwjglopenal20100824librarylwjglopenal-20100824.jar;C:UsersPeterAppDataRoaming.techniccachecompaulscodesoundsystem20120107soundsystem-20120107.jar;C:UsersPeterAppDataRoaming.techniccacheargoargo2.25_fixedargo-2.25_fixed.jar;C:UsersPeterAppDataRoaming.techniccacheorgbouncycastlebcprov-jdk15on1.47bcprov-jdk15on-1.47.jar;C:UsersPeterAppDataRoaming.techniccachecomgoogleguavaguava14.0guava-14.0.jar;C:UsersPeterAppDataRoaming.techniccacheorgapachecommonscommons-lang33.1commons-lang3-3.1.jar;C:UsersPeterAppDataRoaming.techniccachecommons-iocommons-io2.4commons-io-2.4.jar;C:UsersPeterAppDataRoaming.techniccachenetjavajinputjinput2.0.5jinput-2.0.5.jar;C:UsersPeterAppDataRoaming.techniccachenetjavajutilsjutils1.0.0jutils-1.0.0.jar;C:UsersPeterAppDataRoaming.techniccachecomgooglecodegsongson2.2.2gson-2.2.2.jar;C:UsersPeterAppDataRoaming.techniccacheorglwjgllwjgllwjgl2.9.0lwjgl-2.9.0.jar;C:UsersPeterAppDataRoaming.techniccacheorglwjgllwjgllwjgl_util2.9.0lwjgl_util-2.9.0.jar;C:UsersPeterAppDataRoaming.technicmodpackstekkitmainbinminecraft.jar net.minecraft.launchwrapper.Launch --username mps_devil --session token:8a86632b83c64e72b81853ea51cbf2cb:2a02f1f36318457abef5eb9ecc537b30 --version 1.6.4-Forge9.11.1.965 --gameDir C:UsersPeterAppDataRoaming.technicmodpackstekkitmain --assetsDir C:UsersPeterAppDataRoaming.technicassetsvirtuallegacy --tweakClass cpw.mods.fml.common.launcher.FMLTweaker --title Tekkit --icon C:UsersPeterAppDataRoaming.technicassetspackstekkitmainicon.png
[b#283]  Mar 17, 2015 10:36:49 PM net.minecraft.launchwrapper.LogWrapper log
[b#283]  INFO: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[b#283]  Mar 17, 2015 10:36:50 PM net.minecraft.launchwrapper.LogWrapper log
[b#283]  INFO: Using primary tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[b#283]  Mar 17, 2015 10:36:50 PM net.minecraft.launchwrapper.LogWrapper log
[b#283]  INFO: Calling tweak class cpw.mods.fml.common.launcher.FMLTweaker
[b#283]  2015-03-17 22:36:50 [iNFO] [ForgeModLoader] Forge Mod Loader version 6.4.49.965 for Minecraft 1.6.4 loading
[b#283]  2015-03-17 22:36:50 [iNFO] [ForgeModLoader] Java is Java HotSpot 64-Bit Server VM, version 1.8.0_31, running on Windows 8.1:amd64:6.3, installed at C:Program FilesJavajre1.8.0_31
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod codechicken.core.launch.DepLoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod appeng.transformer.AppEngCore does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:50 [iNFO] [ForgeModLoader] [AppEng] Core Init
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod calclavia.lib.CalclaviaPluginLoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod codechicken.core.launch.CodeChickenCorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283] Analytics Response [runModpack]: 200
[b#283]  2015-03-17 22:36:50 [iNFO] [sTDERR] Warning: version of ForgeMultipart-universal-1.6.4-, 1.0.0.250 is newer than request 1.0.0.244
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod cofh.asm.LoadingPlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod mods.immibis.microblocks.coremod.MicroblocksCoreMod does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:50 [WARNING] [ForgeModLoader] The coremod invtweaks.forge.asm.FMLPlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod logisticspipes.asm.LogisticsPipesCoreLoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod micdoodle8.mods.miccore.MicdoodlePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod codechicken.nei.asm.NEICorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod openmods.OpenModsCorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod codechicken.core.launch.DepLoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod mrtjp.projectred.compatibility.CompatibilityCorePlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod universalelectricity.core.UELoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [WARNING] [ForgeModLoader] The coremod codechicken.core.launch.DepLoader does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[b#283]  2015-03-17 22:36:51 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[b#283]  2015-03-17 22:36:51 [iNFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
[b#283]  2015-03-17 22:36:51 [iNFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[b#283]  2015-03-17 22:36:51 [sEVERE] [ForgeModLoader] Unable to launch
[b#283]  java.util.ConcurrentModificationException
[b#283]      at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
[b#283]      at java.util.ArrayList$Itr.remove(Unknown Source)
[b#283]      at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)
[b#283]      at net.minecraft.launchwrapper.Launch.main(Launch.java:27)
[b#283]  Java HotSpot 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0
[b#283] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552547.png?1426455520, with 3 tries remaining

​

[Brandy01]

Same problem 

[EvilOwl]

LegacyJavaFixer. Find it. Add it to the mods directory.

Edit: link for the lazy