If you are developing new site, you have probably locked it through htpasswd. When you are done with og meta data, you might want to check it with https://developers.facebook.com/tools/debug/sharing/ – but facebook won’t be able to access your content, because you can’t give it your password.
You need to update your htaccess, from
AuthUserFile /.htpasswd
AuthName Disbait
AuthType Basic
Require valid-user
satisfy any
deny from all
allow from 127.0.0.1
to
SetEnvIfNoCase User-Agent "^facebookexternalhit" facebook
SetEnvIfNoCase User-Agent "Facebot" facebook
SetEnvIfNoCase User-Agent "Twitterbot" twitter
AuthUserFile /.htpasswd
AuthName "Restricted Access"
AuthType Basic
Require valid-user
satisfy any
deny from all
allow from 127.0.0.1
allow from env=facebook
allow from env=twitter