Well, I've tried reinstalling, getting a clean MC copy, tried different versions of Forge but I still get this crash report on startup whenever I try to add any mod to Forge (BiblioCraft in this report):

 

 

 

      Minecraft has crashed!     

      ----------------------     

 

Minecraft has stopped running because it encountered a problem; Failed to start game

 

A full error report has been saved to C:\Users\user\AppData\Roaming\.minecraft\crash-reports\crash-2013-03-05_03.04.39-client.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash

 

 

 

--- BEGIN ERROR REPORT 5cf7c98a --------

Full report at:

C:\Users\user\AppData\Roaming\.minecraft\crash-reports\crash-2013-03-05_03.04.39-client.txt

Please show that file to Mojang, NOT just this screen!

 

Generated 03:04 05/03/13

 

-- System Details --

Details:

Minecraft Version: 1.4.7

Operating System: Windows 7 (x86) version 6.1

Java Version: 1.7.0_15, Oracle Corporation

Java VM Version: Java HotSpot Client VM (mixed mode), Oracle Corporation

Memory: 407829032 bytes (388 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)

JVM Flags: 2 total; -Xms512m -Xmx1024m

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 v7.26 FML v4.7.4.520 Minecraft Forge 6.6.0.497 4 mods loaded, 4 mods active

mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed

FML [Forge Mod Loader] (coremods) Unloaded->Constructed

Forge [Minecraft Forge] (coremods) Unloaded->Constructed

BiblioCraft [biblioCraft] (jds) Unloaded->Errored

LWJGL: 2.4.2

OpenGL: GeForce GTX 650/PCIe/SSE2 GL version 4.2.0, 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

 

cpw.mods.fml.common.LoaderException: java.lang.ClassNotFoundException: jds.bibliocraft.BiblioCraft

at cpw.mods.fml.common.LoadController.transition(LoadController.java:117)

at cpw.mods.fml.common.Loader.loadMods(Loader.java:485)

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(Unknown Source)

Caused by: java.lang.ClassNotFoundException: jds.bibliocraft.BiblioCraft

at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:185)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at cpw.mods.fml.common.ModClassLoader.loadClass(ModClassLoader.java:57)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Unknown Source)

at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:416)

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: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:140)

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: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:83)

at cpw.mods.fml.common.Loader.loadMods(Loader.java:479)

... 5 more

Caused by: java.lang.NullPointerException

at org.objectweb.asm.ClassReader.<init>(Unknown Source)

at net.minecraftforge.transformers.EventTransformer.transform(EventTransformer.java:29)

at cpw.mods.fml.relauncher.RelaunchClassLoader.runTransformers(RelaunchClassLoader.java:228)

at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:173)

... 32 more

--- END ERROR REPORT 13071fb8 ----------

You've done something wrong in your installation of your mod, not a forge issue.