I need to test some extensive code behind logic for a report I am developing, so I added a Windows form project to my solution that contains the class library with the report in it. I added the necessary reference to my code library and set the window form as the start up form. I added the Report Viewer and the correct reference to my report in the Report property. So far no problem. When I attempt to generate the report however, I get the following message "An error has occurred while processing Report 'report object name' Unable to establish connection to the database." etc. I have verified my database connection. I have no problem previewing the report from my class library. It generates just fine but with invalid data, thus the need to single step through my logic. What am I missing in setting up this testing environment. thanks in advance.