Do you always have a default/index page?

<introEmbed body={<> Many times a website contains directories that don't have an index page, and this means a user navigating via the URL, see a 404 error. You don't want this to happen, so make sure you always have an index page in every directory, even if it's just to show the files inside it. </>} />

It is usually a default.aspx file, however depending on the webserver configuration; it might be index.html or index.php etc.