answer:404 is pretty unambiguous, something is wrong with your link URL for “books” (in your example). Some guesses 1) If you’re using relative links (<a href=”./books”>) then you may not be “starting” where you think you are. Check your current URL and make sure it’s as expected. WordPress does a ton of redirecting depending on how you have your permalinks set up 2) Make sure you have permalinks set up how you’re expecting 3) If you aren’t using “pretty” permalinks in the Settings, all bets are off 4) If you’re having wordpress generate the menu, or iterating through an array you’re pulling, output the whole thing (print_r($links) for example) and make sure you’re using the right attribute and it contain exactly what you’re expecting. Similar items have slightly different versions of URLs, you can check the codex, but usually just dumping the whole thing to the page is quicker and more definitive for development 5) remember you might have a root defined for categories or for the your post type, something like www.yourawesomesite.com/categoryies/thiscategory/ A link to your site would probably tell a lot more, but maybe start with those?