There are many reasons for this error, I would like to share my finding regarding this.
After migrating CRM 4 to 2011, I received this error for most of the reports, Digging into Reporting Service Logs, I found the following error,
Microsoft.Crm.Reporting.DataExtensionShim.Common.ReportExecutionException: Microsoft.Crm.CrmException: An unexpected error occurred. System.ServiceModel.EndpointNotFoundException: Could not connect to net.tcp://test23/CrmSandboxSdkListener-w3wp. The connection attempt lasted for a time span of 00:00:21.0091007. TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 172.xx.x.xx:808. System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 172.xx.x.xx:808. --->
The solution is to, add Inbound Rule in Windows Firewall (in CRM Server) for tcp protocol using port 808
After migrating CRM 4 to 2011, I received this error for most of the reports, Digging into Reporting Service Logs, I found the following error,
Microsoft.Crm.Reporting.DataExtensionShim.Common.ReportExecutionException: Microsoft.Crm.CrmException: An unexpected error occurred. System.ServiceModel.EndpointNotFoundException: Could not connect to net.tcp://test23/CrmSandboxSdkListener-w3wp. The connection attempt lasted for a time span of 00:00:21.0091007. TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 172.xx.x.xx:808. System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 172.xx.x.xx:808. --->
The solution is to, add Inbound Rule in Windows Firewall (in CRM Server) for tcp protocol using port 808