Black Screen when updating Forge

[rafael80]

2012-09-19 19:15:02 [iNFO] [ForgeModLoader] Forge Mod Loader version 3.1.15.378 for Minecraft client:1.3.2, server:1.3.2 loading

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] All core mods are successfully located

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Discovering coremods

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Found library file argo-2.25.jar present and correct in lib dir

 

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Found library file guava-12.0.1.jar present and correct in lib dir

 

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Found library file asm-all-4.0.jar present and correct in lib dir

 

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Running coremod plugins

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Running coremod plugin FMLCorePlugin

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Coremod plugin FMLCorePlugin run successfully

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Running coremod plugin FMLForgePlugin

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Coremod plugin FMLForgePlugin run successfully

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Validating minecraft

2012-09-19 19:15:02 [FINEST] [ForgeModLoader] Minecraft validated, launching...

2012-09-19 19:15:02 [iNFO] [sTDERR] Exception in thread "Thread-10" java.lang.RuntimeException: cpw.mods.fml.relauncher.ReflectionHelper$UnableToFindClassException: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-09-19 19:15:02 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:261)

2012-09-19 19:15:02 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:204)

2012-09-19 19:15:02 [iNFO] [sTDERR] at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:28)

2012-09-19 19:15:02 [iNFO] [sTDERR] at net.minecraft.Launcher.replace(Launcher.java:136)

2012-09-19 19:15:02 [iNFO] [sTDERR] at net.minecraft.Launcher$1.run(Launcher.java:79)

2012-09-19 19:15:02 [iNFO] [sTDERR] Caused by: cpw.mods.fml.relauncher.ReflectionHelper$UnableToFindClassException: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-09-19 19:15:02 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.ReflectionHelper.getClass(ReflectionHelper.java:159)

2012-09-19 19:15:02 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:246)

2012-09-19 19:15:02 [iNFO] [sTDERR] ... 4 more

2012-09-19 19:15:02 [iNFO] [sTDERR] Caused by: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.net.URLClassLoader$1.run(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.net.URLClassLoader$1.run(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.security.AccessController.doPrivileged(Native Method)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.net.URLClassLoader.findClass(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.lang.Class.forName0(Native Method)

2012-09-19 19:15:02 [iNFO] [sTDERR] at java.lang.Class.forName(Unknown Source)

2012-09-19 19:15:02 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.ReflectionHelper.getClass(ReflectionHelper.java:151)

2012-09-19 19:15:02 [iNFO] [sTDERR] ... 5 more

 

[Zero]

Please see my post here. it pretty much explains what you need to do.

[luacs1998]

This error can be caused when not using a forge-compatible launcher.

Use the launchers linked by the post above this one.