"This field name is not known" issue

Hi SAP TechSupport Team!

I have unresolved issue related to "This field name is not known" error while running my report via ReportDocument's function Export(). Before that I correctly gave all required parameters. This report work fine if I am using it with ReportViewer. I could not understand reason of that error. Please help to resolve this.

CrystalReports is being used is the 10.5 version, in VS 2008. That report was created in CrystalReport 8.5 old version

Thanks in advance

Vasil Avagyan