495 SSL Certificate Error
HTTP response status code 495 SSL Certificate Error is an unofficial client error specific to nginx and is returned by the server to indicate that there has been an error with the client certificate verification.
Usage
When the 495 SSL Certificate Error status code is received, the client has sent an invalid SSL certificate with the HTTP request. This is related to error 400 Bad Request. To solve this error, the HTTP request needs to be resubmitted with a valid SSL certificate.
Note
Search engines like Google will not index a URL with 495 SSL Certificate Error response status, and consequently, URLs that have been indexed in the past but are now returning this HTTP status code will be removed from the search results.
Takeaway
The 495 SSL Certificate Error status code is a client error that is sent by the server when the client submits an HTTP request with an invalid SSL certificate.