I installed Forge 4.0.0 for 1.3.1 (yes it's there) the way the wiki told me to, but when I start up Minecraft, I get a black screen.

I tried it with the console and this is what happens:

 

 

Forge Mod Loader version 3.0.15.247 for Minecraft client:1.3.1, server:1.3.1 loader

Exception in thread "Thread-10" java.lang.RuntimeException: java.lang.NullPointerException

at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:162)

at cpw.mods.fml.relauncher.FMLRelauncher.relauncherApplet(FMLRelauncher.java:212)

at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:190)

at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:25)

at net.minecraft.Launcher.replace(Launcher.java:136)

at net.minecraft.Launcher$1.run(Launcher.java:79)

Caused by: java.lang.NullPointerException

at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:75)

at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:142)

... 5 more

 

 

 

 

Does anyone know what's going on?

There is no client version of forge for minecraft 1.3.1 yet.

 

Please use the search next time and read  the sticky's:

http://www.minecraftforge.net/forum/index.php/topic,1200.0.html

No Havaro you can download the client version for Minecraft 1.3.1 right here install the same as any other version.

 

http://jenkins.minecraftforge.net:7070/job/forge/182/