I saw a new language in the Minecraft settings, and I selected it. The game immediately crashed, and I can't even get to the main menu without crashing. I also use other mods :P

Here is the report:
---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 2/5/14 3:39 PM
Description: MCA: Error while loading language.

java.lang.NullPointerException
at java.util.Properties$LineReader.readLine(Unknown Source)
at java.util.Properties.load0(Unknown Source)
at java.util.Properties.load(Unknown Source)
at mca.core.util.LanguageHelper.loadLanguage(LanguageHelper.java:78)
at mca.core.util.LanguageHelper.loadLanguage(LanguageHelper.java:58)
at mca.core.MCA.preInit(MCA.java:1061)
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:545)
at sun.reflect.GeneratedMethodAccessor5.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:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
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:201)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:181)
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:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
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:112)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:522)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:183)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:473)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
at net.minecraft.client.main.Main.main(SourceFile:101)
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:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

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

-- System Details --
Details:
Minecraft Version: 1.6.4
Operating System: Windows 8 (x86) version 6.2
Java Version: 1.7.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 121940176 bytes (116 MB) / 336211968 bytes (320 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
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 v8.11 FML v6.4.49.965 Minecraft Forge 9.11.1.965 82 mods loaded, 82 mods active
mcp{8.09} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized
FML{6.4.49.965} Forge Mod Loader Unloaded->Constructed->Pre-initialized
Forge{9.11.1.965} Minecraft Forge Unloaded->Constructed->Pre-initialized
AppliedEnergistics-Core{rv13.c} AppliedEnergistics Core Unloaded->Constructed->Pre-initialized
CodeChickenCore{0.9.0.7} CodeChicken Core Unloaded->Constructed->Pre-initialized
NotEnoughItems{1.6.1.5} [Not Enough Items](NotEnoughItems 1.6.1.5.jar) Unloaded->Constructed->Pre-initialized
TConstruct-Preloader{0.0.1} Tinkers Corestruct Unloaded->Constructed->Pre-initialized
DamageIndicatorsMod{2.9.1.1} [Damage Indicators](1.6.4 DamageIndicatorsv2.9.1.1.zip) Unloaded->Constructed->Pre-initialized
battlegear2{1.0.4.6} Mine & Blade Battlegear 2 - Bullseye Unloaded->Constructed->Pre-initialized
pixelartist{2.0j} PixelArtist Unloaded->Constructed->Pre-initialized
xtrablocksdiycloth{2.0} XtraBlocksDIYCloth Unloaded->Constructed->Pre-initialized
xtrablocksdiydecorations{2.0j} XtraBlocksDIYDecorations Unloaded->Constructed->Pre-initialized
xtrablocksdiydiscs{1.6} XtraBlocksDIYDiscs Unloaded->Constructed->Pre-initialized
xtrablocksdiyfencing{2.0j} XtraBlocksDIYFencing Unloaded->Constructed->Pre-initialized
xtrablocksdiyfood{1.6} XtraBlocksDIYFood Unloaded->Constructed->Pre-initialized
xtrablocksdiyglass{2.0} XtraBlocksDIYGlass Unloaded->Constructed->Pre-initialized
xtrablocksdiyglow{2.0} XtraBlocksDIYGlow Unloaded->Constructed->Pre-initialized
xtrablocksdiyliquids{2.0j} XtraBlocksDIYLiquids Unloaded->Constructed->Pre-initialized
xtrablocksdiymetal{2.0} XtraBlocksDIYMetal Unloaded->Constructed->Pre-initialized
xtrablocksdiypanels{2.0j} XtraBlocksDIYPanels Unloaded->Constructed->Pre-initialized
xtrablocksdiystone{2.0} XtraBlocksDIYStone Unloaded->Constructed->Pre-initialized
xtrablocksdiyweapons{2.0j} XtraBlocksDIYWeapons Unloaded->Constructed->Pre-initialized
xtrablocksdiywood{2.0} XtraBlocksDIYWood Unloaded->Constructed->Pre-initialized
xtrablocksmiscmodels{1.0} XtraBlocksMiscModels Unloaded->Constructed->Pre-initialized
xtrablockstombs{1.0} XtraBlocksTombs Unloaded->Constructed->Pre-initialized
xtrablocksdiystorage{2.0j} XtraBlocksDIYStorage Unloaded->Constructed->Pre-initialized
xtrablocksdiyadmin{2.0j} XtraBlocksDIYAdmin Unloaded->Constructed->Pre-initialized
xtrablocksdiypowered{2.0j} XtraBlocksDIYPowered Unloaded->Constructed->Pre-initialized
xtrablocksdiyxtras{2.0j} XtraBlocksDIYXtras Unloaded->Constructed->Pre-initialized
xtrablocksfurniture{1.0} XtraBlocksFurniture Unloaded->Constructed->Pre-initialized
xtrablocksbuildings{1.0} XtraBlocksBuildings Unloaded->Constructed->Pre-initialized
bspkrsCore{v4.3(1.6.4)} bspkrsCore Unloaded->Constructed->Pre-initialized
mod_bspkrsCore{v4.3(1.6.4)} bspkrsCore Unloaded->Constructed->Pre-initialized
TreeCapitator{Forge 1.6.4.r04} Treecapitator Unloaded->Constructed->Pre-initialized
AppliedEnergistics{rv13.c} Applied Energistics Unloaded->Constructed->Pre-initialized
Artifice{1.6.4R1.1.3} Artifice Unloaded->Constructed->Pre-initialized
ArtificeCompat|EE3{1.6.4R1.1.3} Artifice Compat: EE3 Unloaded->Constructed->Pre-initialized
ArtificeCompat|Forestry{1.6.4R1.1.3} Artifice Compat: Forestry Unloaded->Constructed->Pre-initialized
ArtificeCompat|Vanilla{1.6.4R1.1.3} Artifice Compat: Vanilla Unloaded->Constructed->Pre-initialized
BattleTowers{1.4.2} Battle Towers Unloaded->Constructed->Pre-initialized
BetterDungeons{2.4} Chocolate quest Unloaded->Constructed->Pre-initialized
BuildCraft|Core{4.1.0} BuildCraft Unloaded->Constructed->Pre-initialized
BuildCraft|Builders{4.1.0} BC Builders Unloaded->Constructed->Pre-initialized
BuildCraft|Energy{4.1.0} BC Energy Unloaded->Constructed->Pre-initialized
BuildCraft|Factory{4.1.0} BC Factory Unloaded->Constructed->Pre-initialized
BuildCraft|Transport{4.1.0} BC Transport Unloaded->Constructed->Pre-initialized
BuildCraft|Silicon{4.1.0} BC Silicon Unloaded->Constructed->Pre-initialized
builder{0.6.0} Builder Unloaded->Constructed->Pre-initialized
BWG4{1.1.9} Better World Generation 4 Unloaded->Constructed->Pre-initialized
Cheating-Essentials{4.2.1} Cheating Essentials Reloaded Unloaded->Constructed->Pre-initialized
ChickenChunks{1.3.3.3} [ChickenChunks](ChickenChunks 1.3.3.3.jar) Unloaded->Constructed->Pre-initialized
ComputerCraft{1.57} ComputerCraft Unloaded->Constructed->Pre-initialized
CCTurtle{1.57} ComputerCraft Turtles Unloaded->Constructed->Pre-initialized
IC2{2.0.282-experimental} IndustrialCraft 2 Unloaded->Constructed->Pre-initialized
DartCraft{Beta 0.2.10} [DartCraft](DartCraft Beta 0.2.10.jar) Unloaded->Constructed->Pre-initialized
DragonMounts{r33} Dragon Mounts Unloaded->Constructed->Pre-initialized
eplus{1.16.5b} Enchanting Plus Unloaded->Constructed->Pre-initialized
ExtrabiomesXL{3.14.5} ExtrabiomesXL Unloaded->Constructed->Pre-initialized
extracells{1.6.7b} ExtraCells Unloaded->Constructed->Pre-initialized
FGM{3.0.0} [Ferullo's Gun Mod](FGM3 BETA_1.zip) Unloaded->Constructed->Pre-initialized
flenixcities{0.6.1} FlenixCities Unloaded->Constructed->Pre-initialized
fc_largebuildings{0.2.0} FlenixCities LargeBuildings Unloaded->Constructed->Pre-initialized
fc_office{0.2.0} FlenixCities Office Unloaded->Constructed->Pre-initialized
inventorytweaks{1.56} Inventory Tweaks Unloaded->Constructed->Pre-initialized
mca{3.5.4} [Minecraft Comes Alive](MCA v3.5.4-1.zip) Unloaded->Constructed
numina{0.0.1-17} Numina Unloaded->Constructed
powersuits{0.8.0-18} MachineMuse's Modular Powersuits Unloaded->Constructed
more{0.0.1} MOre Unloaded->Constructed
moreplayermodels{1.6.4} MorePlayerModels Unloaded->Constructed
Morph{0.6.0} Morph Unloaded->Constructed
PetBat{1.2.8} Pet Bat Unloaded->Constructed
Roguelike{1.2.9} Roguelike Dungeons Unloaded->Constructed
silvania{0.2} Silvania Unloaded->Constructed
TConstruct{1.6.X_1.5.0d} Tinkers' Construct Unloaded->Constructed
TConstruct|CompatAE{0.0.1} TConstruct Compat: AE Unloaded->Constructed
TConstruct|ForgeMuliPart{0.1} TConstruct Compat: FMP Unloaded->Constructed
TConstruct|CompatMineFactoryReloaded{0.2} TConstruct Compat: MFR Unloaded->Constructed
TConstruct|PeaceOfMind{1.0} TConstruct|PeaceOfMind Unloaded->Constructed
TConstruct|CompatWaila{0.0.1} TConstruct Compat: Waila Unloaded->Constructed
AS_UpdateCheck{1.1.1} AtomicStryker Update Check Mod Unloaded->Constructed
UsefulFood{1.4.4} [UsefulFood](UsefulFood-1.6.2_1.4.4 %281%29.zip) Unloaded->Constructed
weaponmod{1.6.2 v1.13.6} Balkon's WeaponMod Unloaded->Constructed

What language did you try to load?

To resolve this, remove MCA, start Minecraft, set the language back to the language you had selected before, then reinstall MCA.

It is called HAYO- I dont now (IC)