I am trying to generate a report using SSRS 2008. During report processing i am facing an error which states.."An error has occured during report processing .Query execution failed for dataset (datasetno).A severe error occured opn the current command.The results if any,should be discarded.Operation cancelled by user ". The datasetname for which query execution is failing is changing randomly.When I am executing those dataset queries seperately it was not throwing any errors.Sometimes I am getting my report without any failure. I am really fix in this issue.Don't have any clue how to solve this error. plz anyone help me. Thanks in advance.