in reply to "This site is not secure" warning message
Safari (OS/X) is presently throwing this error ... sometimes, but not always:
"*.pairsite.com" certificate does not match input.
The SSL certificate must match the actual domain-name, not that of its host. I cordially suggest that the site owners should obtain a free SSL certificate from letsencrypt.org and arrange to renew it every 90 days like everybody else does.
Right now, I see an inconsistency between secure and not-secure pages on this site. Some pages are, others aren’t. And, those that are, are throwing this error. (For example, the web-page in which I am right now typing this response does not display a padlock icon.)
(Believe me, I feel for you, most patiently, as you work through these issues on such an old web-site.)