Hi George, I'll try that. Bit pushed this morning, but as soon as I get a chance ... I'd love to be able to supply you with an example file, too, but unfortunately it contains private data (e.g. disability data) about students at our institution - so for DPA reasons, I can't easily release a copy of the file to you. The output file is a government return, and you can see the detail about the makeup of the file by visiting the public web site: http://www.hesa.ac.uk/index.php?option=com_studrec&Itemid=232&mnl=07051 You can download the schemas from there, for example - and a sample XML file. The sample XML file is, of course, much smaller than our return. Our return contains details of over 11,000 students along with all their courses (in the thousands), all the modules associated with those courses (in the thousands), and all the enrolments of students on modules (in the tens of thousands at least). Given the schema, you might perhaps be able to generate some data?? Cheers Peter -----Original Message----- From: George Cristian Bina [mailto:george@oxygenxml.com] Sent: 08 October 2008 11:04 To: Bradley, Peter Cc: oXygen User ML Subject: Re: [oXygen-user] Large XML file Hi Peter, oXygen provide also a tree based editor that is available as a tool, see Tools->Tree Editor (CTRL+T) and also as a separate application see the Oxygen Tree Editor (treeEditor.exe) launcher. Please try also that and see if that helps. It will be interesting for us to perform some tests with your file that you had problems with so if you can make that available please let us know on support@oxygenxml.com how to get access to it (it will not work to just attach it to an email). One thing that may render the format and indent on open useless is the possible presence of an xml:space="preserve" attribute eventually on the root element or on some element with a large content. Best Regards, George -- George Cristian Bina <oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger http://www.oxygenxml.com