When you run your query, it might run just find but in your stimulsoft report you might get this error. The error could arise from mismatch of parameter or parameter not giving in the URL or too many parameters given. In my case the error was really dump. I was referencing a report that did not exists. That is my report was refering to report1new.mrt which did not exist. I should have been referring to report1.mrt instead. After fixing this error went away.
Hope it helps someone else! A simple spelling mistake!