Quote Originally Posted by infogate View Post
There are several reasons. However, the most common reason is server being unable to verify the Certification Authority (CA), who created the certificate.

To solve the issue, please, check with your hosting provider to verify if the local SSL libraries (list of valid Certification Authorities) are up to date.

Have a look here for a possible solution
Thank you. I have sent hosting message and waiting for update. I have tried curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); and it shows following error message:

"Status: array (
0 => '',
)


Fatal error: Uncaught OAuthException: An active access token must be used to query information about the current user. thrown in /home/suppgeek/public_html/facebook_authorization.php on line 533"