12:39:03] [Sound Library Loader/INFO]: Sound engine started
[12:39:04] [Client thread/INFO]: Created: 1024x512 textures/blocks-atlas
[12:39:04] [Client thread/INFO]: Created: 512x512 textures/items-atlas
[12:39:04] [Client thread/ERROR]: Fatal errors were detected during the transition from INITIALIZATION to POSTINITIALIZATION. Loading cannot continue
[12:39:04] [Client thread/ERROR]:
mcp{9.03} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized
FML{7.2.203.1095} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized
Forge{10.12.1.1095} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized
inventorytweaks{1.57-116} Inventory Tweaks Unloaded->Constructed->Pre-initialized->Errored
[12:39:04] [Client thread/ERROR]: The following problems were captured during this phase
[12:39:04] [Client thread/ERROR]: Caught exception from inventorytweaks
java.lang.IllegalAccessError: tried to access field net.minecraft.client.settings.KeyBinding.field_74512_d from class invtweaks.InvTweaksObfuscation
at invtweaks.InvTweaksObfuscation.getKeyBindingForwardKeyCode(InvTweaksObfuscation.java:102) ~[InvTweaksObfuscation.class:?]
at invtweaks.InvTweaksHandlerShortcuts.loadShortcuts(InvTweaksHandlerShortcuts.java:76) ~[InvTweaksHandlerShortcuts.class:?]
at invtweaks.InvTweaksConfigManager.loadConfig(InvTweaksConfigManager.java:144) ~[InvTweaksConfigManager.class:?]
at invtweaks.InvTweaksConfigManager.makeSureConfigurationIsLoaded(InvTweaksConfigManager.java:59) ~[InvTweaksConfigManager.class:?]
at invtweaks.InvTweaks.(InvTweaks.java:105) ~[InvTweaks.class:?]
at invtweaks.forge.ClientProxy.init(ClientProxy.java:40) ~[ClientProxy.class:?]
at invtweaks.forge.InvTweaksMod.init(InvTweaksMod.java:36) ~[InvTweaksMod.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_55]
at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513) ~[FMLModContainer.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_55]
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74) ~[guava-15.0.jar:?]
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:267) ~[guava-15.0.jar:?]
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208) ~[LoadController.class:?]
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187) ~[LoadController.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_55]
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74) ~[guava-15.0.jar:?]
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296) ~[guava-15.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:267) ~[guava-15.0.jar:?]
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118) [LoadController.class:?]
at cpw.mods.fml.common.Loader.initializeMods(Loader.java:690) [Loader.class:?]
at cpw.mods.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:288) [FMLClientHandler.class:?]
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:527) [azd.class:?]
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:815) [azd.class:?]
at net.minecraft.client.main.Main.main(SourceFile:103) [Main.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_55]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_55]
at magic.launcher.Launcher.main(SourceFile:207) [MagicLauncher_1.2.5.exe:?]
---- Minecraft Crash Report ----
// Ouch. That hurt :(

Only 1 mod is used to generate the error.
-- System Details --
Details:
Minecraft Version: 1.7.2
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_55, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 354251608 bytes (337 MB) / 518979584 bytes (494 MB) up to 518979584 bytes (494 MB)
JVM Flags: 3 total; -Xms512m -Xmx512m -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump
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 v7.2.203.1095 Minecraft Forge 10.12.1.1095 4 mods loaded, 4 mods active
mcp{9.03} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized
FML{7.2.203.1095} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized
Forge{10.12.1.1095} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized
inventorytweaks{1.57-116} Inventory Tweaks Unloaded->Constructed->Pre-initialized->Errored

@!@# Game crashed! Crash report saved to: #@!@# C:\Users\benjamincharlton\AppData\Roaming.minecraft\crash-reports\crash-2014-05-26_12.39.04-client.txt

AL lib: (EE) alc_cleanup: 1 device not closed

test edit

Just to clarify I can use this same install and run voxelmap (another mod) ok...

You should post logs if you're reporting things. And say what's actually happening, not just what version of Forge you're using.

1. The logs are in the first post...
2. It shows what version of Minecraft (1.7.2)
3. The log shows exactly whats happening....

mcp{9.03} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized
FML{7.2.203.1095} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized
Forge{10.12.1.1095} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized
inventorytweaks{1.57-116} Inventory Tweaks Unloaded->Constructed->Pre-initialized->Errored
[12:39:04] [Client thread/ERROR]: The following problems were captured during this phase
[12:39:04] [Client thread/ERROR]: Caught exception from inventorytweaks
java.lang.IllegalAccessError: tried to access field
net.minecraft.client.settings.KeyBinding.field_74512_d from class invtweaks.InvTweaksObfuscation

As you can see inventory tweaks is trying the keybind but gets IllegalAccessError.

Honestly did you even read the post and not just the title...

The post was empty when I replied, you probably just edited that in.

Anyway, you're installing it incorrectly, magic launcher normally doesn't work right -- it needs to be in the mods folder, nowhere else.

That's weird regarding the post...I definitely posted the logs when I created the issue...mind you I did create the issue and edited them 1 minute after creation.

I will have a go without using a magiclauncher...to be fair though - I have used magic launcher with 90% of the client mods with no issues...