What is a Soft 404 error?
 

Hello, experts please tell me what is a soft 404 error?

A soft 404 means that a URL on your site returns a page telling the user that the page does not exist and also a 200-level (success) code to the browser. (In some cases, instead of a "not found" page, it might be a page with little or no usable content--for example, a sparsely populated or empty page.)

Since you're new to the forum, try to ask better questions which are not at least easily searchable.

Google announced they added “soft” or “crypto” 404s to their “crawl errors” report in Google Webmaster Tools. Soft 404s or crypto 404s are page not found pages that return the server response code of 200. Technically, 404 pages should return a server status code 404, which means page not found.

Soft 404s or crypto 404s are page not found pages that return the server response code of 200.Contains the correct content and properly returns a 200 response.