I also reported this to RWTema the extra utilities dev.
---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 5/4/14 11:44 AM
Description: Initializing game

java.lang.NoClassDefFoundError: codechicken/microblock/ItemMicroPart
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.ProxyInjector.inject(ProxyInjector.java:59)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:492)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:209)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:188)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:489)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:202)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:815)
at net.minecraft.client.main.Main.main(SourceFile:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: codechicken.microblock.ItemMicroPart
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:188)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 35 more
Caused by: java.lang.NullPointerException
at org.objectweb.asm.ClassReader.(Unknown Source)
at invtweaks.forge.asm.ContainerTransformer.transform(ContainerTransformer.java:112)
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:276)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:174)
... 37 more

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

-- Head --
Stacktrace:
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.ProxyInjector.inject(ProxyInjector.java:59)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:492)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:209)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:188)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:489)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:202)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:815)
at net.minecraft.client.main.Main.main(SourceFile:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.7.2
Operating System: Windows 8 (amd64) version 6.2
Java Version: 1.8.0, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 161866456 bytes (154 MB) / 307232768 bytes (293 MB) up to 954728448 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v9.03 FML v7.2.165.1063 Minecraft Forge 10.12.1.1063 51 mods loaded, 51 mods active
mcp{9.03} Minecraft Coder Pack Unloaded->Constructed
FML{7.2.165.1063} Forge Mod Loader Unloaded->Constructed
Forge{10.12.1.1063} Minecraft Forge Unloaded->Constructed
AppliedEnergistics2-Core{rv0-alpha-91} AppliedEnergistics2 Core Unloaded->Constructed
CodeChickenCore{1.0.0} CodeChicken Core Unloaded->Constructed
MCVanillaTweaks{1.0} Mariculture - Vanilla Tweaks Unloaded->Constructed
NotEnoughItems{1.0.1} Not Enough Items Unloaded->Constructed
TConstruct-Preloader{0.1.1} Tinkers Corestruct Unloaded->Constructed
ThaumicTinkerer-preloader{0.1} Thaumic Tinkerer Core Unloaded->Constructed
IC2{2.1.470-experimental} IndustrialCraft 2 Unloaded->Constructed
AdvancedMachines{1.0.7} IC2 Advanced Machines Addon Unloaded->Constructed
Mantle{1.7.2-132.45b0b50} Mantle Unloaded->Constructed
TConstruct{1.7.2-1.6.0.jenkins478} Tinkers' Construct Unloaded->Constructed
aobd{1.4.1} Another One Bites The Dust Unloaded->Constructed
BuildCraft|Core{5.0.5} BuildCraft Unloaded->Constructed
appliedenergistics2{rv0-alpha-91} Applied Energistics 2 Unloaded->Constructed
bdlib{1.3.0.8} BD Lib Unloaded->Constructed
examplemod{1.0} [examplemod](Botania beta-24.jar) Unloaded->Constructed
Botania{beta-24} [Botania](Botania beta-24.jar) Unloaded->Constructed
BuildCraft|Builders{5.0.5} BC Builders Unloaded->Constructed
BuildCraft|Energy{5.0.5} BC Energy Unloaded->Constructed
BuildCraft|Factory{5.0.5} BC Factory Unloaded->Constructed
BuildCraft|Transport{5.0.5} BC Transport Unloaded->Constructed
BuildCraft|Silicon{5.0.5} BC Silicon Unloaded->Constructed
CarpentersBlocks{3.1.2} [Carpenter's Blocks](Carpenter's Blocks v3.1.2 - MC 1.7+.zip) Unloaded->Constructed
denseores{1.0} denseores Unloaded->Constructed
Baubles{1.0.0.10} Baubles Unloaded->Constructed
Thaumcraft{4.1.1.11} Thaumcraft Unloaded->Constructed
Electro-MagicTools{1.1.0} Electro-MagicTools Unloaded->Constructed
Enchiridion{1.0a} Enchiridion Unloaded->Constructed
ExtraUtilities{1.1.0-prerelease-1b} Extra Utilities Unloaded
Forestry{2.4.0.0-711} Forestry for Minecraft Unloaded
gendustry{1.2.0.8} GenDustry Unloaded
HopperDuctMod{1.3} Hopper Ducts Unloaded
inventorytweaks{1.57-116} Inventory Tweaks Unloaded
IronChest{6.0.14.719} Iron Chest Unloaded
JABBA{1.1.3} Jabba Unloaded
Railcraft{@Version@} Railcraft Unloaded
Mariculture{b2} Mariculture Unloaded
mythril{1.5} Mythril mod Unloaded
Morpheus{1.7.2-1.3} Morpheus Unloaded
movillages{1.2.0} Mo' Villages Unloaded
cfm{3.2.9.2} §6MrCrayfish's Furniture Mod Unloaded
clayspawn{1.7.2a} [Pam's Clay Spawn](Pam's Clay Spawn 1.7.2a.zip) Unloaded
PneumaticCraft{1.1.5} PneumaticCraft Unloaded
RedstonePasteMod{1.6.1} Redstone Paste Unloaded
RefinedRelocation{1.0.4a} Refined Relocation Unloaded
symcalc{0.12} Symcalc Unloaded
ThaumicTinkerer{alpha-2.3-89} Thaumic Tinkerer Unloaded
TMechworks{1.7.2-60.0ab3ef0} Tinkers' Mechworks Unloaded
utilities3{A3.1} Utilities³ Unloaded
Mantle Environment: Environment healthy.
TConstruct Environment: Environment healthy.
AE2 Version: alpha rv0-alpha-91 for Forge 10.12.0.1024
AE2 Integration: RotaryCraft:ON, IC2:ON, BC:ON, MJ:ON, RF:ON, MFR:ON, DSU:ON, FZ:ON, Waila:ON, RB:ON, InvTweaks:ON, NEI:ON, CraftGuide:ON, FMP:ON
Launched Version: 1.7.2-Forge10.12.1.1063
LWJGL: 2.9.0
OpenGL: Intel(R) HD Graphics GL version 3.1.0 - Build 9.17.10.2843, Intel
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: ERROR NullPointerException: null
Anisotropic Filtering: Off (1)

#56