"FeatureNotSupportedException" running joined report through analytics api

Question

Getting the exception while trying to run the joined report through analytics api report manager.

reports.FeatureNotSupportedException: You’re requesting data for an unsupported report format.
Error is in expression '{!getReportContent}' in component in page reportexport: Class.reports.ReportManager.runAsyncReport: line 33, column 1
Class.ReportExportController.getReportContent: line 71, column 1

Here running the report Asynchronously

 Reports.ReportInstance reportInstance = Reports.ReportManager.runAsyncReport(reportID, true);

Its supporting for the Summary,Tabular and Matrix reports running successfully but where as for joined reports its raising exception mentioned above.

Answer 1

1. After Reading some documents came to know that for standard joined reports there was no ExportDetail option available in salesforce. And also this salesforce analytics api won't supports joined(MultiBlock) reports,where as it supports for other three Tabular,Summary and Matrix.