Hi, I send you a some code to illustrate a strange behavior with Xquery update. The code is as simple as possible to illustrate my purpose. I’ve placed a Xquery update function in a Xquery module (module.xql), this function is then called from a query (request.xquery). when I execute this code within OxygenXml, it return me the error : Engine name: Saxon-EE XQuery 9.4.0.4 Severity: error Description: Node to be deleted is not an updateable node URL: http://www.saxonica.com/documentation/javadoc/net/sf/saxon/trans/SaxonErrorC... unless I add in the query a comment like (: copy modify :), in this case, the code work fine! I have tried to execute this sample from the Saxon command line : $ java -cp /usr/local/lib/oxygen-xml/lib/saxon9ee.jar net.sf.saxon.Query -update:on request.xquery No license file found - running with licensable features disabled Error SXUP0081: Target node of insert expression is not updateable at mod:transform-update-test() (file:/home/nicolas/git-clones/xquery-dev/src/xquery-update/modify-copy-bugs/request.xquery#4) Query processing failed: Run-time errors were reported I’ve got a error with or without the comment (: copy modify :), and the execution is ok when I had the option -tree:linked on the command line, with or without the comment. $ java -cp /usr/local/lib/oxygen-xml/lib/saxon9ee.jar net.sf.saxon.Query -update:on -tree:linked request.xquery No license file found - running with licensable features disabled <?xml version="1.0" encoding="UTF-8"?><modify-copy-bugs><hello>world</hello> </modify-copy-bugs> I work with Oxygen Version : XML Editor 14.2, build 2013021115 on Ubuntu 12.04. Regards, Nicolas BUONOMO -- Nicolas BUONOMO CNAF - CNEDI Rhône Alpes DSI - Direction Fonctionnelle et Processus Relation avec les Collectivités Territoriales Tél : 0478636669 / 0677877811 Mél : nicolas buonomo@cnafmail.fr