MacOS – View TLS Certificate in Safari 8 / Yosemite

Recent versions of Safari do not appear to display the lock icon or certificate unless all content loaded by the page is https. For example, if the page URL is https but it loads a JavaScript file via http, no lock icon.

The only workaround I've found so far is to run the openssl command in Terminal, like this:

echo ^d | openssl s_client -connect host.example.com:443

This will show you the certificate chain back to whatever root authority is used to sign, if any. "verify error" will show things like "self signed certificate".

I would check Activity Monitor while you are clicking the Safari icon. See if there are any processes like "Safari" or "Safari Web Content" that is showing up, and see if there is a red "not responding". This probably will not happen if the app does not even bounce, but it's worth a try. You can also try basic things like right clicking, clicking "Show all windows" or going to Options and clicking asking to this desktop. Also, have you been working with multiple displays recently? The safari window may be "stuck" on the other display, so you should check it out by plugging any back in.