Mac Mindcrack closing on startup

[Matrixrider]

just today ive been getting on mindcrack and it gets to the mojang screen, then it crashes and has this error report, if it doesnt paste right, it will be attached.


If you can tell me how to fix it, please help.

---- Minecraft Crash Report ----
// This is a token for 1 free hug. Redeem at your nearest Mojangsta: [~~HUG~~]

Time: 2/23/13 4:45 PM
Description: Failed to start game

cpw.mods.fml.common.LoaderException: java.lang.ClassNotFoundException: invtweaks.InvTweaksMod
at cpw.mods.fml.common.LoadController.transition(LoadController.java:130)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:504)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:161)
at net.minecraft.client.Minecraft.a(Minecraft.java:410)
at asq.a(SourceFile:56)
at net.minecraft.client.Minecraft.run(Minecraft.java:744)
at java.lang.Thread.run(Thread.java:680)
Caused by: java.lang.ClassNotFoundException: invtweaks.InvTweaksMod
at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:185)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at cpw.mods.fml.common.ModClassLoader.loadClass(ModClassLoader.java:57)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:249)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:418)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
at com.google.common.eventbus.EventBus.post(EventBus.java:268)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:153)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
at com.google.common.eventbus.EventBus.post(EventBus.java:268)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:86)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:494)
... 5 more
Caused by: java.lang.UnsupportedClassVersionError: invtweaks/InvTweaksMod : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:174)
... 31 more


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
Minecraft Version: 1.4.7
Operating System: Mac OS X (x86_64) version 10.6.8
Java Version: 1.6.0_41, Apple Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
Memory: 201760064 bytes (192 MB) / 266272768 bytes (253 MB) up to 2143158272 bytes (2043 MB)
JVM Flags: 5 total; -Xms256M -Xmx2048M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+AggressiveOpts
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v7.26a FML v4.7.32.553 Minecraft Forge 6.6.1.524 Feed The Beast Mod Pack 60 mods loaded, 60 mods active
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed
FML [Forge Mod Loader] (coremods) Unloaded->Constructed
Forge [Minecraft Forge] (coremods) Unloaded->Constructed
CodeChickenCore [CodeChicken Core] (coremods) Unloaded->Constructed
NotEnoughItems [Not Enough Items] (coremods) Unloaded->Constructed
CoFHCore [CoFH Core] (CoFHCore.zip) Unloaded->Constructed
BuildCraft|Core [BuildCraft] (buildcraft.jar) Unloaded->Constructed
ComputerCraft [ComputerCraft] (computercraft.zip) Unloaded->Constructed
CCTurtle [ComputerCraft Turtles] (computercraft.zip) Unloaded->Constructed
ThermalExpansion [Thermal Expansion] (thermalexpansion.zip) Unloaded->Constructed
OmniTools [OmniTools] (omnitools.zip) Unloaded->Constructed
IC2 [IndustrialCraft 2] (IC2.jar) Unloaded->Constructed
TwilightForest [The Twilight Forest] (TwilightForest.zip) Unloaded->Constructed
BuildCraft|Builders [BC Builders] (buildcraft.jar) Unloaded->Constructed
BuildCraft|Energy [BC Energy] (buildcraft.jar) Unloaded->Constructed
BuildCraft|Factory [BC Factory] (buildcraft.jar) Unloaded->Constructed
BuildCraft|Transport [BC Transport] (buildcraft.jar) Unloaded->Constructed
BuildCraft|Silicon [BC Silicon] (buildcraft.jar) Unloaded->Constructed
factorization [Factorization] (factorization.jar) Unloaded->Constructed
ExtrabiomesXL [ExtrabiomesXL] (extrabiomes.jar) Unloaded->Constructed
Forestry [Forestry for Minecraft] (forestry.jar) Unloaded->Constructed
Railcraft [Railcraft] (railcraft.jar) Unloaded->Constructed
RedPowerCore [RedPower] (redpowercore.zip) Unloaded->Constructed
RedPowerBase [RP Base] (redpowercore.zip) Unloaded->Constructed
RedPowerMachine [RP Machine] (redpowermechanical.zip) Unloaded->Constructed
RedPowerCompat [RP Compat] (redpowercompat.zip) Unloaded->Constructed
RedPowerWiring [RP Wiring] (redpowerdigital.zip) Unloaded->Constructed
RedPowerLogic [RP Logic] (redpowerdigital.zip) Unloaded->Constructed
RedPowerLighting [RP Lighting] (redpowerdigital.zip) Unloaded->Constructed
RedPowerWorld [RP World] (redpowermechanical.zip) Unloaded->Constructed
RedPowerControl [RP Control] (redpowermechanical.zip) Unloaded->Constructed
ThermalExpansion|Factory [Factory] (thermalexpansion.zip) Unloaded->Constructed
ThermalExpansion|Energy [Energy] (thermalexpansion.zip) Unloaded->Constructed
ThermalExpansion|Transport [Transport] (thermalexpansion.zip) Unloaded->Constructed
XyCraft [XyCraft] (xycraft.zip) Unloaded->Constructed
GregTech_Addon [GregTech-Addon] (GregTech.zip) Unloaded->Constructed
IC2NuclearControl [Nuclear Control] (IC2NuclearControl.zip) Unloaded->Constructed
inventorytweaks_forge [Inventory Tweaks (Forge)] (InvTweaks.jar) Unloaded->Errored
IronChest [Iron Chest] (IronChest.zip) Unloaded->Constructed
PortalGun [Portal Gun] (PortalGun.zip) Unloaded->Constructed
StevesCarts [Steve's Carts] (StevesCarts.zip) Unloaded->Constructed
Thaumcraft [Thaumcraft] (Thaumcraft.zip) Unloaded->Constructed
AdvancedMachines [IC2 Advanced Machines Addon] (advancedmachines.zip) Unloaded->Constructed
AdvancedSolarPanel [Advanced Solar Panels] (advancedsolarpanel.zip) Unloaded->Constructed
ChickenChunks [ChickenChunks] (chickenchunks.jar) Unloaded->Constructed
EnderStorage [EnderStorage] (enderstorage.jar) Unloaded->Constructed
BinnieCore [Binnie Core] (extrabees.zip) Unloaded->Constructed
ExtraBees [Extra Bees] (extrabees.zip) Unloaded->Constructed
GraviSuite [Gravitation Suite] (gravisuite.zip) Unloaded->Constructed
MiscPeripherals [MiscPeripherals] (miscperipherals.jar) Unloaded->Constructed
ModularForceFieldSystem [Modular ForceField System V2] (modularforcefieldsystem.zip) Unloaded->Constructed
NEIPlugins [NEI Plugins] (neiplugins.jar) Unloaded->Constructed
ObsidiPlates [Obsidian Pressure Plates] (obsidiplates.zip) Unloaded->Constructed
TC [Traincraft] (traincraft.jar) Unloaded->Constructed
drceph.petrogen [Petroleum Generator] (petrogen.zip) Unloaded->Constructed
mod_ReiMinimap [mod_ReiMinimap] (reiminimap.zip) Unloaded->Constructed
SoulShards [SoulShards] (soulshards.zip) Unloaded->Constructed
WR-CBE|Core [WR-CBE Core] (wirelessredstonecore.jar) Unloaded->Constructed
WR-CBE|Addons [WR-CBE Addons] (wirelessredstoneaddons.jar) Unloaded->Constructed
WR-CBE|RedPower [WR-CBE RedPower] (wirelessredstoneredpower.jar) Unloaded->Constructed
LWJGL: 2.4.2
OpenGL: NVIDIA GeForce 8600M GT OpenGL Engine GL version 2.1 NVIDIA-1.6.36, NVIDIA Corporation
Is Modded: Definitely; Client brand changed to 'forge,fml'
Type: Client (map_client.txt)
Texture Pack: Default
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null

 

[Scaffolding]

Inventory Tweaks seems to be your problem. If you are fine with an unofficial version I recommend Kobata's Invtweaks 1.50b or 1.50c as they are supposed to be Java 6 compatible.

Please let me know if this helps.