In 404 Manager you can track all 404 errors appeared to visitors or search engines
In this page, you will just see the top visited 404 error links ..
The difference between this screen and Redirect Manager is that these rules are only applied when …
The General Rules are lowest priority that 404 Rules they will be applied when ..
Some times many 404 errors appear in Discovered 404 Errors tab, most of them targeted to /wp-content/ folder ..