i faced this problem when I used Mantle related mods and rail craft, when removed both the game starts just fine. I tried re-installing the game, deleting assets, checked for mods duplicates and version compatibility and re-installing java and installing x64-bit java version. none worked.

---- Minecraft Crash Report ----
// Ooh. Shiny.

Time: 5/9/14 3:25 PM
Description: Initializing game

java.lang.RuntimeException: java.io.FileNotFoundException: minecraft:font/glyph_sizes.bin
at mantle.client.block.SmallFontRenderer.readGlyphSizes(SmallFontRenderer.java:234)
at mantle.client.block.SmallFontRenderer.<init>(SmallFontRenderer.java:150)
at tconstruct.client.TProxyClient.registerRenderer(TProxyClient.java:308)
at tconstruct.TConstruct.preInit(TConstruct.java:132)
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 cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513)
at sun.reflect.GeneratedMethodAccessor3.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:208)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
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:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:500)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
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.io.FileNotFoundException: minecraft:font/glyph_sizes.bin
at net.minecraft.client.resources.SimpleReloadableResourceManager.func_110536_a(SourceFile:58)
at mantle.client.block.SmallFontRenderer.readGlyphSizes(SmallFontRenderer.java:229)
... 39 more


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

-- Head --
Stacktrace:
at mantle.client.block.SmallFontRenderer.readGlyphSizes(SmallFontRenderer.java:234)
at mantle.client.block.SmallFontRenderer.<init>(SmallFontRenderer.java:150)
at tconstruct.client.TProxyClient.registerRenderer(TProxyClient.java:308)
at tconstruct.TConstruct.preInit(TConstruct.java:132)
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 cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513)
at sun.reflect.GeneratedMethodAccessor3.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:208)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
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:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:500)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
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 8.1 (amd64) version 6.3
Java Version: 1.7.0_55, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 189604760 bytes (180 MB) / 512229376 bytes (488 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 v7.2.172.1073 Minecraft Forge 10.12.1.1073 39 mods loaded, 39 mods active
mcp{9.03} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized
FML{7.2.172.1073} [Forge Mod Loader] (forge-1.7.2-10.12.1.1073.jar) Unloaded->Constructed->Pre-initialized
Forge{10.12.1.1073} [Minecraft Forge] (forge-1.7.2-10.12.1.1073.jar) Unloaded->Constructed->Pre-initialized
AppliedEnergistics2-Core{rv0-alpha-113} [AppliedEnergistics2 Core] (minecraft.jar) Unloaded->Constructed->Pre-initialized
CodeChickenCore{1.0.0} [CodeChicken Core] (minecraft.jar) Unloaded->Constructed->Pre-initialized
NotEnoughItems{1.0.1} [Not Enough Items] (NotEnoughItems-1.7.2-1.0.1-universal.jar) Unloaded->Constructed->Pre-initialized
TConstruct-Preloader{0.1.1} [Tinkers Corestruct] (minecraft.jar) Unloaded->Constructed->Pre-initialized
IC2{2.1.477-experimental} [industrialCraft 2] (industrialcraft-2-2.1.477-experimental.jar) Unloaded->Constructed->Pre-initialized
AdvancedMachines{1.0.8} [iC2 Advanced Machines Addon] (AdvancedMachinesAS-1.7.2.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Core{6.0.10} [buildCraft] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
appliedenergistics2{rv0-alpha-113} [Applied Energistics 2] (appliedenergistics2-rv0-alpha-113.jar) Unloaded->Constructed->Pre-initialized
thebombzenapi{2.3.5} [ThebombzenAPI] (ThebombzenAPI-v2.3.5-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized
autoswitch{4.3.4} [AutoSwitch] (AutoSwitch-v4.3.4-mc1.7.2.jar) Unloaded->Constructed->Pre-initialized
BaMsGRAVE{1.4.1} [baM's Grave] (bamsgrave-1.7.2-1.4.1.jar) Unloaded->Constructed->Pre-initialized
BiblioCraft{1.6.3} [biblioCraft] (BiblioCraft[1.6.3][MC1.7.2].jar) Unloaded->Constructed->Pre-initialized
AWWayofTime{v1.0.0d} [AlchemicalWizardry] (Blood Magic-v1.0.0d.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Builders{6.0.10} [bC Builders] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Energy{6.0.10} [bC Energy] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Factory{6.0.10} [bC Factory] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Transport{6.0.10} [bC Transport] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
BuildCraft|Silicon{6.0.10} [bC Silicon] (buildcraft-6.0.10.jar) Unloaded->Constructed->Pre-initialized
kegare.caveworld{1.3.3} [Caveworld] (Caveworld_1.7.2-v1.3.3.jar) Unloaded->Constructed->Pre-initialized
ForgeMultipart{1.1.0.278} [Forge Multipart] (ForgeMultipart-1.7.2-1.1.0.278-universal.jar) Unloaded->Constructed->Pre-initialized
McMultipart{1.1.0.278} [Minecraft Multipart Plugin] (ForgeMultipart-1.7.2-1.1.0.278-universal.jar) Unloaded->Constructed->Pre-initialized
inventorytweaks{1.57-116} [inventory Tweaks] (InventoryTweaks-1.57-116.jar) Unloaded->Constructed->Pre-initialized
IronChest{6.0.14.719} [iron Chest] (ironchest-1.7.2-6.0.14.719-universal.jar) Unloaded->Constructed->Pre-initialized
reaper_lantern{1.44} [Lantern mod] (Lantern1.44[1.7.2].jar) Unloaded->Constructed->Pre-initialized
Mantle{1.7.2-132.45b0b50} [Mantle] (Mantle-1.7.2-0.2.8.jar) Unloaded->Constructed->Pre-initialized
moreplayermodels{1.7.2} [MorePlayerModels] (MorePlayerModels_1.7.2.jar) Unloaded->Constructed->Pre-initialized
Natura{2.2.0} [Natura] (natura-1.7.2-2.2.0a3.jar) Unloaded->Constructed->Pre-initialized
ObsidianBoat{v1.3.2} [Obsidian Boat] (ObsidianBoat-1.7.2-1.3.2.jar) Unloaded->Constructed->Pre-initialized
PneumaticCraft{1.1.8} [PneumaticCraft] (PneumaticCraft-1.1.8.jar) Unloaded->Constructed->Pre-initialized
secretroomsmod{@VERSION@} [The SecretRoomsMod] (secretroomsmod-1.7.2-4.6.3.349.jar) Unloaded->Constructed->Pre-initialized
Waila{1.5.2_1.7.2} [Waila] (Waila-1.5.2a_1.7.2.jar) Unloaded->Constructed->Pre-initialized
TConstruct{1.7.2-1.6.0.jenkins478} [Tinkers' Construct] (TConstruct-1.7.2-1.6.0.a14.jar) Unloaded->Constructed->Errored
Baubles{1.0.0.11} [baubles] (Baubles-1.7.2-1.0.0.11.jar) Unloaded->Constructed->Pre-initialized
Thaumcraft{4.1.1.12} [Thaumcraft] (Thaumcraft-1.7.2-4.1.1.12.jar) Unloaded->Constructed->Pre-initialized
TMechworks{1.7.2-60.0ab3ef0} [Tinkers' Mechworks] (TMechworks-1.7.2-0.2.7.jar) Unloaded->Constructed->Errored
ForgeMicroblock{1.1.0.278} [Forge Microblocks] (ForgeMultipart-1.7.2-1.1.0.278-universal.jar) Unloaded->Constructed->Pre-initialized
AE2 Version: alpha rv0-alpha-113 for Forge 10.12.0.1024
AE2 Integration: RotaryCraft:OFF, IC2:ON, RC:ON, BC:ON, MJ:ON, RF:OFF, InvTweaks:ON, MFR:ON, DSU:ON, FZ:ON, Waila:ON, RB:ON, InvTweaks:ON, NEI:ON, CraftGuide:ON, FMP:ON
Mantle Environment: Environment healthy.
TConstruct Environment: Environment healthy.
Launched Version: 1.7.2-Forge10.12.1.1073
LWJGL: 2.9.0
OpenGL: GeForce 9400 GT/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
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)

Go to the forum thread then. This is a forum for Forge problems, and this is clearly not one of them.