New Post: TFS 2012 build server error

Can anyone shed any light on this error I'm getting on our TFS 2012 build server?

Chutzpah Error: System.NullReferenceException: Object reference not set to an instance of an object.

at Chutzpah.TestHarness.BuildTags(IEnumerable'1 referencedFilePaths)

at Chutzpah.TestContextBuilder.CreateTestHarness(IFrameworkDefinition definition, ChutzpahTestSettingsFile chutzpahTestSettings, String inputTestFilePath, IEnumerable'1 referencedFiles, ICoverageEngine coverageEngine, IList'1 temporaryFiles)

at Chutzpah.TestContextBuilder.BuildContext(PathInfo file, TestOptions options)

at Chutzpah.TestContextBuilder.TryBuildContext(PathInfo file, TestOptions options, TestContext& context)

at Chutzpah.TestRunner.<>c__DisplayClass2.<ProcessTestPaths>b__1(PathInfo testFile)
While Running:C:...UI\Tests\unit\moof.spec.js

Thanks!