Now, if your template included elements in the w15 namespace which are in the package org/docx4j/w15, docx4j would keep them, so you'd have to remove them to get a pure 2010 format document
But, if I am correct, your answer is about adding a 2013 template to a 2010 document.
But what I really need is 'converting' the 2013 template to a 2010 template.
Or should I create an empty 2010 document, add the 2013 template and save the new document as 2010 template? (Is that at all possible because I have not used docx4j yet, just looking for a solution to this problem).
The issue has nothing to do with docx4j but with my app but I hope that docx4j will come to a rescue
The attached templates are from Word 2010 and 2013.
When using the 2010 template the new document comes out fine. When using the 2013 template the new document comes out without any text from the template..