JavaError Bouncycastle

Hello Forge Community,

I hope you can help me solving this problem:

When I install the ForgeMod (doesn't matter wich version) my game freezes at loading/generating a World.

I tried with other Mods installed and without also different versions(for Minecraft1.4.6).

This is the Error showing up in the log:

2012-12-25 18:49:01 [iNFO] [sTDERR] java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider

2012-12-25 18:49:01 [iNFO] [sTDERR] at bdz.c(IntegratedServer.java:99)

2012-12-25 18:49:01 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)

2012-12-25 18:49:01 [iNFO] [sTDERR] at fy.run(SourceFile:849)

2012-12-25 18:49:01 [iNFO] [sTDERR] Caused by: java.lang.ClassNotFoundException: org.bouncycastle.jce.provider.BouncyCastleProvider

2012-12-25 18:49:01 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:179)

2012-12-25 18:49:01 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-12-25 18:49:01 [iNFO] [sTDERR] at java.lang.ClassLoader.loadClass(Unknown Source)

2012-12-25 18:49:01 [iNFO] [sTDERR] ... 3 more

2012-12-25 18:49:01 [iNFO] [sTDERR] Caused by: java.lang.NullPointerException

2012-12-25 18:49:01 [iNFO] [sTDERR] at org.objectweb.asm.ClassReader.<init>(Unknown Source)

2012-12-25 18:49:01 [iNFO] [sTDERR] at net.minecraftforge.transformers.EventTransformer.transform(EventTransformer.java:29)

2012-12-25 18:49:01 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.runTransformers(RelaunchClassLoader.java:222)

2012-12-25 18:49:01 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:171)

2012-12-25 18:49:01 [iNFO] [sTDERR] ... 5 more

2012-12-25 18:49:01 [iNFO] [sTDERR] java.lang.NullPointerException

2012-12-25 18:49:01 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:358)

2012-12-25 18:49:01 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.k(MinecraftServer.java:406)

2012-12-25 18:49:01 [iNFO] [sTDERR] at bdz.k(IntegratedServer.java:231)

2012-12-25 18:49:01 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:550)

2012-12-25 18:49:01 [iNFO] [sTDERR] at fy.run(SourceFile:849)

Make sure you have the lib bcprov-jdk15on-147.jar in your libs/ folder...

Thank you soooo much!