kklosson Thank you for the offer. I have meanwhile discovered that if I use a .docx file as template, it works as long as I define it as an MS Word document, not the “MS Word (XML)” type document. Strange, because as far I know the .docx format is in fact an XML document.
Unfortunately, when using a .docx template the resulting file that is provided by the server (i.e. downloaded to the end user’s computer) is still a .doc file and not a .docx file. Apparently the original .docx file is converted to .doc by the server in the process of creating the merged file. Do you have that too or can you get the server to provide a generated .docx file?
(If relevant: both my server and the user computer are running on Windows).
Furthermore, I managed to implement the User Defined Document feature, which enables me to edit and replace the template from the end user’s computer instead of the configutor. This solves the 2nd issue. As an additional benefit I can now define multiple templates and then select the one that I want to use, so there is much more flexibility.