If you get an InfoJetException exception throwed by InfoJetSoft.Service.Util.CABFileFinder.findCABFile while registering form templates(xsn), please add the key <add key="InfoJetSoft.Service.TempFolder" value="c:\log" /> to your Web.config. Then please grant the full control of "c:\log" to everyone. By default, InfoJet Service needs to extract the files in form templates(xsn) to the system temp directory. But in some condition(such as impersonation is enabled), InfoJet Service has no perms to do it, so please add this key.

In JScript/VBScript, please use the following code to access DataObject:
XDocument.DataObjects.item( "DataObjectName" ).DOM ,
rather than XDocument.DataObjects[] or XDocument.DataObjects().

InfoJet Service have to cache the query result of the secondary data source for receiving data into http session, so it will cost many memory if the data source returns a big data. Using StateServer or SQLServer mode session state management could improve the robustness. And you could cache the data source in ASP.NET Cache to save memory by using the configuration element "DataObjectCache".