The error is that when a batch (about 15) of similar 1 page documents are sent to the printer from the server some of them (last time it was 5) fail with the message ‘Invalid printer specified’ and the others work fine. The same document sent 1 second later will work fine. We are using. Winodws 2008 R2 Std server (64 Bites) C# version 4 Crystal API version 13.2 Printer: HP LaserJet 600 M602 This is error message I'm getting. An error of type COMException occured with message " Invalid printer specified. GBPickList {FBC22A8B-E19A-438A-923A-F44EEDB861BD}.rpt". Target Site:Void ModifyPrinterName(System.String), stack: at CrystalDecisions.ReportAppServer.Controllers.PrintOutputControllerClass.ModifyPrinterName(String newVal) at CrystalDecisions.CrystalReports.Engine.PrintOptions.set_PrinterName(String value)