In the LTS version of 4D, clicking “Structure Definition to an HTML File” generates an XML file along with a linked XSL stylesheet. This setup was originally designed to allow users to view and print the database structure directly from a web browser. However, today’s modern browsers (Safari, Chrome, Edge, Firefox) have disabled local XML + XSL rendering for security reasons. As a result, simply opening the XML file doesn’t display the structured output.

Instead of trying to open XML files directly in the browser, you can transform your XML file into an HTML file using an XSLT processor. This method gives you a clean, browser-compatible HTML output.
here is an example : miyako/4d-utility-structure-to-html