GWT is reporting 404 crawl errors on pages that have never been part of the website.
For example, it's reporting crawl errors on several non-existent pages such as mysite.net/blog/how-can-i-improve-seo-ranking. On the 'Linked from' tab, it lists several internal pages that don't even have this page linked from. Also on the 'Linked from' tab, it lists the sitemap, which is updated once a week and never has links to these non-existent pages.
I am unable to figure out what exactly is causing this- is it something to do with the website itself or is GWT wrongly identifying pages? If these pages are not even listed on the sitemap or linked from any of the internal pages, why is GWT reporting this? Does anyone know how to fix this?