Hello Darren,
Thanks for writing in! Usually, it is caused by a broken code that has been inserted on the page. I have checked your page and I found that you have inserted a broken code in your footer content. You added this:
<p>proudly built by <a href="http://www.design-munky.com" style="color: #318ad2; title="Ook Ook!">Design Munky</a></p>
You need to update it and insert this code instead:
<p>proudly built by <a href="http://www.design-munky.com" style="color: #318ad2;" title="Ook Ook!">Design Munky</a></p>
What’s the difference? You missed inserting the closing quotation mark for the style attribute. After that changes, check the page again if the missing 404s are still present. Clear all your caches first before testing the site again.
Best Regards.