When running a Crystal Report(V10) I get the error message 'Can not obtain error message from server'

My report is running over a Domino database, connecting two views to together with a single join (Left outer join, not enforced).

If I run the report I get a different error message 'Failed to open a rowset' followed by 'Inavlid Argument Provided@

Can anyone help me by indicating the likley cause of, or to diagnose the problem?