4xx errors
IssueHigh priority
Resources that answered with a 4xx status, such as 404 Not Found.
Why it matters
The address is linked from somewhere but gives visitors nothing, and search engines drop pages that stay this way.
How to fix it
Restore the page, or redirect its address to the closest replacement, and update the links listed under Links In.
Skitter runs this check on every crawl, and lists each page it finds with the evidence: the header, the tag or the link that gave it away.