crystal report missing paramater database log on fail

Question

Hi,

I'm trying to convert crystal report file to pdf in c#.  Each month my crystal report is getting refreshed. I have unchecked "Save data with report" so the file automatically refreshes every month.  I do not show this files in the crystal report viewer. If I check "Save data with report" everything works fine. If I don't, first, I was getting database logon failed. Then I have added connection to database. Now I get Missing parameter.

This is how I load crystal file:

string fileName = Path.GetFileName(reportPath);
            ReportDocument report = new ReportDocument();
            report.Load(reportPath);
//added this line
            report.SetDatabaseLogon("username", "password", "server", "database");
            //added this line
            report.Refresh();

Any suggestions on how I can fix this problem?

Thank you.