i had a black screen with mineshafter on this i posted on their forum they replied: Check on the forge forums.

so heres the log.

 

[Mineshafter Squared] C:\Users\Jesse\AppData\Roaming\.mineshaftersquared/mineshaftersquared.properties

Current proxy version: 3.8.0

Gotten proxy version: 3.8.0

Trying to proxy on port 9010

Proxying successful

asdf

Request: GET http://mcupdate.tumblr.com/

No handler. Piping.

Piping finished, data size: 25522

Request: GET http://static.tumblr.com/qfn3sex/ezom7y7iq/bg_main.png

No handler. Piping.

Piping finished, data size: 434

Request: GET http://pixel.quantserve.com/pixel/p-19UtqE8ngoZbM.gif

No handler. Piping.

Piping finished, data size: 35

executePost: http://session.minecraft.net/game/getversion.jsp

Request: POST http://session.minecraft.net/game/getversion.jsp

GetVersion

To: http://mineshaftersquared.com/game/getversion/3.8.0

2012-08-26 14:59:39 [iNFO] [ForgeModLoader] Forge Mod Loader version 3.0.71.289 for Minecraft client:1.3.2, server:1.3.2 loading

2012-08-26 14:59:44 [iNFO] [sTDERR] Exception in thread "Thread-10" java.lang.RuntimeException: cpw.mods.fml.relauncher.ReflectionHelper$UnableToFindClassException: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-08-26 14:59:44 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:269)

2012-08-26 14:59:44 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:212)

2012-08-26 14:59:44 [iNFO] [sTDERR] at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:25)

2012-08-26 14:59:44 [iNFO] [sTDERR] at net.minecraft.Launcher.replace(Launcher.java:136)

2012-08-26 14:59:44 [iNFO] [sTDERR] at net.minecraft.Launcher$1.run(Launcher.java:79)

2012-08-26 14:59:44 [iNFO] [sTDERR] Caused by: cpw.mods.fml.relauncher.ReflectionHelper$UnableToFindClassException: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-08-26 14:59:44 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.ReflectionHelper.getClass(ReflectionHelper.java:161)

2012-08-26 14:59:44 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:254)

2012-08-26 14:59:44 [iNFO] [sTDERR] ... 4 more

2012-08-26 14:59:44 [iNFO] [sTDERR] Caused by: java.lang.ClassNotFoundException: net.minecraft.Launcher

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.net.URLClassLoader$1.run(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.net.URLClassLoader$1.run(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.security.AccessController.doPrivileged(Native Method)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.net.URLClassLoader.findClass(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.lang.Class.forName0(Native Method)

2012-08-26 14:59:44 [iNFO] [sTDERR] at java.lang.Class.forName(Unknown Source)

2012-08-26 14:59:44 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.ReflectionHelper.getClass(ReflectionHelper.java:153)

2012-08-26 14:59:44 [iNFO] [sTDERR] ... 5 more

Looks like something is base editing your files other than forge.  Make sure Forge is the only thing in your jar.

Banned for being a mineshafter user. Go buy the fucking game.