Broken Image Links after URL Redirect

Hi,

I recently purchased a new domain, which is what my old domain redirects to. It went smoothly, but all the images are showing up as broken links. When you click on them, you get a 404 error. Their URLs are showing up with my old domain suffix, which I’ve been told is the problem.

I’m following this guide to changing the URL in my database, but I have a few concerns.

1. On point four, it says your site should return a 404 error when you complete the step. Mine didn’t.
2. When I look in General Settings or at my Permalinks page, the URLS already look like I want them to, in the new style.

I’m worried that I’ve done something wrong already. Any advice appreciated, thanks!