This may be a plugin or theme conflict. Please attempt to disable all plugins, and switch to the default Twenty Nineteen theme. If the problem goes away, enable them one by one to identify the source of the problem.
If you can install plugins, install Health Check. On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you, while you’re still logged in, without affecting normal visitors to your site.
Thank you for the reply James.
I believe this site is using a very old theme, or a custom one that was created 5 or 6 years ago. I will speak to the end user and get an idea of how they want to approach this.
One basic change they want is to update their address in the footer. I can get at the underlying footer.php file, is it safe to make the update in there?
If it’s an old theme, that might be why the Customizer doesn’t work. Is the text you want to change in the footer.php file itself?
Yes, the text is in the footer.php. I’m assuming I can just change the text in there?
They also want to change the images in the header, so eventually we need to upgrade the theme. But if we can at least update their address in the footer, that will be a good start.
Yes, if that’s all you need to change, and it’s an old theme, changing it directly in footer.php should work.
In newer themes, you’ll be able to just add widgets to the footer and manage everything inside your Dashboard: https://ww.wp.xz.cn/support/article/wordpress-widgets/
