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.