I tried to export my Zen report to PDF but didn't work.

here is my report 

ClassMethod GeneratePdf() As %String
{
Set Fpath="D:\ItemRpt.pdf"
//Set Fpath="D:\ItemRpt"
Set obj=##class(Business.Report.BSReport).%New()
Set ret=obj.GenerateReport(Fpath,2)
Quit ret
}

LIST didn't work but the Join did, thanks you very much Robert.

As I recall, Nest queries didn't work well if all in the old Cache versions so not sure if they improved it !?

Thanks Guys