Can't open testing client?

When i try to open the testing client the console says this

>=========================================================================================================================
>Executing gradle command: runClient
>Microsoft Windows [Version 6.2.9200]
>(c) 2012 Microsoft Corporation. All rights reserved.
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]>cd forge
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge>SET "JAVA_HOME=C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\jdk\"
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge>SET JAVA_EXE=%JAVA_HOME%\bin\java.exe
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge>SET PATH=%JAVA_HOME%\bin\;%PATH%
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge>gradlew runClient
>****************************
> Powered By MCP:             
> http://mcp.ocean-labs.de/   
> Searge, ProfMobius, Fesh0r, 
> R4wk, ZeuX, IngisKahn, bspkrs
> MCP Data version : unknown
>****************************
>:compileApiJava UP-TO-DATE
>:processApiResources UP-TO-DATE
>:apiClasses UP-TO-DATE
>:sourceMainJava
>FAILURE: Build failed with an exception.
>* What went wrong:
>java.io.FileNotFoundException: C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge\.gradle\2.0\taskArtifacts\cache.properties (The system cannot find the file specified)
>> C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge\.gradle\2.0\taskArtifacts\cache.properties (The system cannot find the file specified)
>* 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: 11.193 secs
>C:\Users\Jon\Documents\MCreator 1.5.6 [1.7.10]\forge>
>Task completed with return code 0 in 11756 milliseconds
>Task return code check OK!

What do i do?