I was getting this error
No authority could be contacted for authentication
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at Microsoft.Crm.ReportingServices2005.ReportingService2005.CreateReport(String Report, String Parent, Boolean Overwrite, Byte[] Definition, Property[] Properties)
   at Microsoft.Crm.Reporting.ReportServer.UploadReport(String path, Byte[] reportDefinition, String name, String description)

along with this error
Stack Trace Info: [MissingParameterException: The 'CRM_CalendarType' parameter is missing a value]
   at Microsoft.Reporting.WebForms.ParametersArea.ValidateAllReportInputsSatisfied()
   at Microsoft.Reporting.WebForms.ReportViewer.OnPreRender(EventArgs e)

This error may have many resons. The resoultion which help me in solving this problem was to first unjoin then again join report server machine to/from domain. 

If above did not help in solving then do the following which is "totally not recommended" and "should not do" in production server
Allow annonymous access and select priviliged user / administrator in ReportServer's virtual directory -> properties -> Directory Security