The URL is incorrect. I assume you are referring to the page at https://www2.abbott-library.com/index.php/new-adult-books/. Wherever you used the other URL, you need to change it to the actual URL.
I wish I knew more about this. (Someone else created and maintained this website for years then passed it to me, and I know NOTHING about WordPress.) When I click on the above link from here or in the WordPress dashboard, the page comes up as it should. No error. It’s only when going to the website outside of the dashboard (through Google search say) that the error comes up when clicking the “button”. I have made no changes to the link (as I don’t know how), and as far as I know has never been changed or altered since the website was created. So, sadly, I don’t even know how to change it to the actual URL as from my end it is the same as it’s always been.
Oh. What I notice is that for some reason sometimes the last of the URL is changing from new-adult-books or new-adultbooks. It should have the -. In the dashboard however it shows the link with the – between adult and books as it should.
The link I wrote leads to a page. Pages are a type of data record (post type) in WordPress that each have unique URLs. You can find them in the WordPress backend under Pages. See:
Pages screen
If you are logged into the backend and then click on the link I provided above, you will see the page with the dark admin bar at the top. There you will find a link called “Edit Site” which you can use to edit this page. There you can also see and change the URL of the page. The URL is currently “new-adult-books”.
What you find on Google is an incorrect link, but it also exists on the website. You have to find it (preferably via Google) and change it to the correct link I mentioned. To do this, you have to edit the pages that contain this incorrect link. Some editor probably entered it incorrectly before you.
If you have never used WordPress before, I would also recommend watching some basic videos. Take a look here: https://learn.wordpress.org/learning-pathway/user/
I’m able to find the page and edit it. I only delete blocks or add new ones as that’s the only thing the creator said I needed to continue. I have looked at all the “blocks” (ie images) I added as well as any of the 3 other people (ie authors/editorss) who could edit (but haven’t edited in YEARS). All slug and links were the correct URL. It worked fine in June when I added/deleted blocks/images to the page as I tested it as I always do from Google. Sometime in July or August the 404 error came up. After June, no one was on the website until some visited the website and told us the error. I’m at a loss as I can not find anywhere an incorrect URL.
I’m confused. How do you know about the 404 error on this particular page when all pages can be accessed normally? If this URL isn’t linked anywhere and therefore isn’t being used, you can ignore it completely. The page in question already has the correct URL mentioned above.
I only see the error when I search for the website (such as through Google) and click on the button for the page that has our new adult books. Then the 404 error comes up. It’s the only page that does this. But when I go to my dashboard and see the permalink on the right sidebar it’s always the correct one.
Then, for some reason, Google still has the old URL in its index. You can check this using Google Search Console, for example, and also fix it. There is nothing you can do on the WordPress side. It already returns the correct 404 status for a non-existent URL.
I completely agree with @threadi advice here to ignore the error (as eventually Google should reindex the correct URL) or try to fix the correct URL in Google console.
If the error persists (you’re still getting references to the old URL) another approach to solve the issue could be to add a redirection from the old URL to the new URL so every time there’s a request to https://www2.abbott-library.com/index.php/new-adultsbooks/ , WordPress automatically redirects to the right URL https://www2.abbott-library.com/index.php/new-adult-books/
Redirections can be set with a plugin like https://wordpress.org/plugins/redirection/
