Minecraft won't decompile

[insane_gravy]

I am attempting to decompile Minecraft 1.4.2. I have a clean .jar file and the lates version of MCP. After putting everything in place, I run install.cmd. Not too long after, I encounter this error:

 

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 3, Size: 2

        at java.util.ArrayList.rangeCheckForAdd(ArrayList.java:612)

        at java.util.ArrayList.add(ArrayList.java:426)

        at cpw.mods.fml.common.asm.transformers.MCPMerger.processFields(MCPMerger.java:468)

        at cpw.mods.fml.common.asm.transformers.MCPMerger.processClass(MCPMerger.java:384)

        at cpw.mods.fml.common.asm.transformers.MCPMerger.processJar(MCPMerger.java:217)

        at cpw.mods.fml.common.asm.transformers.MCPMerger.main(MCPMerger.java:107)

Decompile Exception: 1

Press any key to continue . . .

 

I have never seen this error before, and I know everything is up to date. How do I solve this?

[LexManos]

Typically this happens when you don't have clean jars, delete everything and try again.

[insane_gravy]

I did that. I downloaded a clean minecraft.jar and minecraft_server.jar. I still get the same problem.

[keepcalm]

Make sure you're using forge 6.0.1.355

[insane_gravy]

That did it. Thanks.