Submitted URL not found (404)

This error seems to be generated even though the page has been removed from both the sitemap and physically from the server.

The Google Search Console help are not totally clear in this regard. My current understanding is that the error should not be triggered if you remove the URL from both the sitemap and your webserver. However, the error seems to be thrown even if this is the case. I can only summise that the URL is referenced from either an external source or is being followed as a consequence of a natural "crawling" process.

In a similar manner to the error: "Excluded - page with redirect" the cause may be that you have either deleted the file/page from the server an have not updated the sitemap. Alternatively the canonical declaration may have a spelling error (in my case I updated some of the pages with a similar name and forgot to update the sitemap), or the sitemap entry is just wrong!

The "Natural Crawl" process

Before I started using GSC and other Google tools I was of the notion that a web page will be crawled if it is referenced from another page that has been indexed. My observation of this is that this is almost certainly the case.

I have been re-structuring this website and I have been intentionally removing some of the old pages from the webserver. This is only after I have created a new page that contained the content of the page that I had seen receiving "Impressions" in the GSC reports.