gradle crash

C:\Users\james\Documents\MinecraftForge>gradlew.bat --stacktrace
This mapping 'stable_20' was designed for MC 1.8.8! Use at your own peril.
#################################################
         ForgeGradle 2.1-SNAPSHOT-9e8f067
  https://github.com/MinecraftForge/ForgeGradle
#################################################
               Powered by MCP unknown
             http://modcoderpack.com
         by: Searge, ProfMobius, Fesh0r,
         R4wk, ZeuX, IngisKahn, bspkrs
#################################################
C:\Users\james\Documents\MinecraftForge\jsons\1.8.9-dev.json could not be parsed

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'forge'.
> java.io.FileNotFoundException: Inherited json file (null) not found! Maybe you are running in offline mode?

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

* Exception is:
org.gradle.api.ProjectConfigurationException: A problem occurred configuring root project 'forge'.
        at org.gradle.configuration.project.LifecycleProjectEvaluator.addConfigurationFailure(LifecycleProjectEvaluator.java:79)
        at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:74)
        at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:61)
        at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:491)
        at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:89)
        at org.gradle.execution.TaskPathProjectEvaluator.configureHierarchy(TaskPathProjectEvaluator.java:42)
        at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:35)
        at org.gradle.initialization.DefaultGradleLauncher$2.run(DefaultGradleLauncher.java:126)
        at org.gradle.internal.Factories$1.create(Factories.java:22)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:52)
        at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:123)
        at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:33)
        at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:100)
        at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:94)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:62)
        at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:94)
        at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:83)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:94)
        at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
        at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:43)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:28)
        at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:77)
        at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:47)
        at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:51)
        at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:28)
        at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:43)
        at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:170)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
        at org.gradle.launcher.Main.doAction(Main.java:33)
        at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
        at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
        at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:30)
        at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:127)
        at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)
Caused by: java.lang.RuntimeException: java.io.FileNotFoundException: Inherited json file (null) not found! Maybe you are running in offline mode?
        at com.google.common.base.Throwables.propagate(Throwables.java:160)
        at net.minecraftforge.gradle.common.BasePlugin.parseAndStoreVersion(BasePlugin.java:737)
        at net.minecraftforge.gradle.patcher.PatcherPlugin.afterEvaluate(PatcherPlugin.java:664)
        at net.minecraftforge.gradle.common.BasePlugin$2.execute(BasePlugin.java:193)
        at net.minecraftforge.gradle.common.BasePlugin$2.execute(BasePlugin.java:185)
        at org.gradle.internal.event.BroadcastDispatch$ActionInvocationHandler.dispatch(BroadcastDispatch.java:93)
        at org.gradle.internal.event.BroadcastDispatch$ActionInvocationHandler.dispatch(BroadcastDispatch.java:82)
        at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:44)
        at org.gradle.internal.event.BroadcastDispatch.dispatch(BroadcastDispatch.java:79)
        at org.gradle.internal.event.BroadcastDispatch.dispatch(BroadcastDispatch.java:30)
        at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
        at com.sun.proxy.$Proxy12.afterEvaluate(Unknown Source)
        at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:67)
        ... 44 more
Caused by: java.io.FileNotFoundException: Inherited json file (null) not found! Maybe you are running in offline mode?
        at net.minecraftforge.gradle.util.json.JsonFactory.loadVersion(JsonFactory.java:136)
        at net.minecraftforge.gradle.util.json.JsonFactory.loadVersion(JsonFactory.java:94)
        at net.minecraftforge.gradle.common.BasePlugin.parseAndStoreVersion(BasePlugin.java:732)
        ... 55 more


BUILD FAILED

Total time: 3.919 secs

C:\Users\james\Documents\MinecraftForge>