Having the same error also; here is my log in case that can help to solve this issue:
*** Starting Minecraft ***
Minecraft version: (modified!) 1.4.6
Minecraft.jar: minecraft.jar
Mods:
Minecraft-Forge-1.4.6.zip
MC 1.4.6 - Player API universal 1.2.zip
SportsMod.zip
Java path: C:\Program Files\Java\jre6\bin\java
Memory: 512 MB
LauncherPath: /C:/Users/FAKE NAME/Downloads/MagicLauncher_1.0.0.exe
*** MagicMinecraftLauncher 1.0.0 ***
Disable inactive mods
2012-12-29 21:49:31 [iNFO] [ForgeModLoader] Forge Mod Loader version 4.6.14.513 for Minecraft 1.4.6 loading
2012-12-29 21:49:32 [iNFO] [ForgeModLoader] Found valid fingerprint for Minecraft Forge. Certificate fingerprint de4cf8a3f3bc15635810044c39240bf96804ea7d
2012-12-29 21:49:34 [iNFO] [sTDOUT] 27 achievements
2012-12-29 21:49:34 [iNFO] [sTDOUT] 210 recipes
2012-12-29 21:49:34 [iNFO] [sTDOUT] Setting user: FAKE NAME, FAKE NUMBER
2012-12-29 21:49:34 [iNFO] [sTDERR] Client asked for parameter: server
2012-12-29 21:49:34 [iNFO] [sTDOUT] LWJGL Version: 2.4.2
2012-12-29 21:49:34 [iNFO] [ForgeModLoader] Attempting early MinecraftForge initialization
2012-12-29 21:49:34 [iNFO] [sTDOUT] MinecraftForge v6.5.0.481 Initialized
2012-12-29 21:49:34 [iNFO] [ForgeModLoader] MinecraftForge v6.5.0.481 Initialized
2012-12-29 21:49:34 [iNFO] [sTDOUT] Replaced 84 ore recipies
2012-12-29 21:49:34 [iNFO] [ForgeModLoader] Completed early MinecraftForge initialization
2012-12-29 21:49:35 [iNFO] [ForgeModLoader] Searching C:\Users\FAKE NAME\AppData\Roaming\.minecraft\mods for mods
2012-12-29 21:49:35 [iNFO] [ForgeModLoader] Attempting to reparse the mod container SportsMod.zip
2012-12-29 21:49:35 [iNFO] [ForgeModLoader] Forge Mod Loader has identified 4 mods to load
2012-12-29 21:49:35 [sEVERE] [ForgeModLoader] Fatal errors were detected during the transition from CONSTRUCTING to PREINITIALIZATION. Loading cannot continue
2012-12-29 21:49:35 [sEVERE] [ForgeModLoader]
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed
FML [Forge Mod Loader] (coremods) Unloaded->Constructed
Forge [Minecraft Forge] (coremods) Unloaded->Constructed
mod_Sports [sports mod] (SportsMod.zip) Unloaded->Errored
2012-12-29 21:49:35 [sEVERE] [ForgeModLoader] The following problems were captured during this phase
2012-12-29 21:49:35 [sEVERE] [ForgeModLoader] Caught exception from mod_Sports
java.lang.NullPointerException
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:445)
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:478)
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)
2012-12-29 21:49:35 [iNFO] [sTDERR] java.lang.NullPointerException
2012-12-29 21:49:35 [iNFO] [sTDERR] at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:445)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.post(EventBus.java:268)
2012-12-29 21:49:35 [iNFO] [sTDERR] at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:140)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
2012-12-29 21:49:35 [iNFO] [sTDERR] at com.google.common.eventbus.EventBus.post(EventBus.java:268)
2012-12-29 21:49:35 [iNFO] [sTDERR] at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:83)
2012-12-29 21:49:35 [iNFO] [sTDERR] at cpw.mods.fml.common.Loader.loadMods(Loader.java:478)
2012-12-29 21:49:35 [iNFO] [sTDERR] at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:161)
2012-12-29 21:49:35 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.a(Minecraft.java:410)
2012-12-29 21:49:35 [iNFO] [sTDERR] at asq.a(SourceFile:56)
2012-12-29 21:49:35 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.run(Minecraft.java:744)
2012-12-29 21:49:35 [iNFO] [sTDERR] at java.lang.Thread.run(Unknown Source)
2012-12-29 21:55:44 [iNFO] [sTDERR] Someone is closing me!
Missing class member: public B c, class: ahn, mod: Minecraft-Forge-1.4.6.zip