BUT if I go to https://mywebsitedev.co.uk/wp-admin I cannot get into the admin panel of WordPress to do anything to my site. Therefore I can’t get to the part on Fixing the WordPress URLs and beyond, which is in the dashboard and settings!
If the site URL’s stored in the WP DB are wrong – i.e. they use a domain that no longer resolves your site – then you won’t be able to fix them in the dashboard because that will be inaccessible until the URL’s are fixed. In this case, you can fix them directly in the database by running some SQL in the “SQL” tab of phpMyAdmin, as I described in Fixing the WordPress URLs.
Until the site URLs in the DB are fixed, the symptom is that many of the links generated by WP go to the old URL, and if you try to log in then login page redirects you to the old URL as well. But apart from that, the site basically “works” outside the admin pages. If you’re seeing directory listings then that points to another issue – I’m not sure what that issue is, but I’d suggest fixing the URLs in the DB first and then see what happens.
