setupDecompWorkspace error

[SwiftyNifty23]

When i try to load it up it give me an error and i did everything that i was supposed to do here is the log

 

#################################################
         ForgeGradle 1.2-SNAPSHOT-fb514d3
  https://github.com/MinecraftForge/ForgeGradle
#################################################
               Powered by MCP unknown
            http://modcoderpack.com
         by: Searge, ProfMobius, Fesh0r,
         R4wk, ZeuX, IngisKahn, bspkrs
#################################################
:extractMcpData UP-TO-DATE
:getVersionJson
:extractUserDev UP-TO-DATE
:genSrgs SKIPPED
:extractNatives UP-TO-DATE
:getAssetsIndex
:getAssets
:makeStart
[ant:javac] warning: [options] bootstrap class path not set in conjunction with -source 1.6
[ant:javac] 1 warning
:downloadMcpTools SKIPPED
:downloadClient SKIPPED
:downloadServer SKIPPED
:mergeJars FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':mergeJars'.
> java.util.zip.ZipException: error in opening zip file

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 11.174 secs

[DaemonUmbra]

I don't know what version of Minecraft you're trying to make mods for but ForgeGradle 1.2 seems to indicate that i's ANCIENT.

[SwiftyNifty23]

I want to create one for 1.7.10