Specific step results drill-down throws the exception (available in the application log): Situation: Unhandled exception! Outer Exception Type: System.NullReferenceException Message: Object reference not set to an instance of an object. HRESULT: 0x80004003 (Official ID (if app.) = E_POINTER, Error Bit = FAILED, Facility = FACILITY_NULL, Code = 16387) Call Stack: at ArtOfTest.WebAii.Design.UI.StepDebug.StepDebugFailureUI.Initialize(AutomationStep step, AutomationStepResult result, TestResult testresult, String resultsPath) at ArtOfTest.WebAii.Design.UI.TestResultsPane.ShowStepFailureDetailsDialog(AutomationStep step, AutomationStepResult stepResult, TestResult testResult) at ArtOfTest.WebAii.Design.UI.TestResultsPane.DrillDownStepResult(StepResultItem item, Boolean updateLastBreadCrumbTitle) at ArtOfTest.WebAii.Design.UI.TestResultsPane.stepResultsGrid_MouseDoubleClick(Object sender, MouseButtonEventArgs e) http://screencast.com/t/Qv9SsedwEay