What it is

The WordPress Plugin could not reach WP Clinic's server over HTTPS because of a TLS/certificate problem on the site's own server — not because WP Clinic's certificate is invalid. It's a valid, publicly trusted certificate with a complete chain. The site's server is the one rejecting it, usually because its local list of trusted certificate authorities is outdated, or a security proxy/antivirus is intercepting outbound HTTPS traffic.

How to fix it

Ask the host to update the OS CA bundle (ca-certificates) and OpenSSL/cURL, and check php.ini for a stale curl.cainfo or openssl.cafile pointing at an old cacert.pem file. If a security proxy or endpoint antivirus inspects outbound HTTPS on that server, allow WP Clinic's API host through it. Never disable certificate verification to work around this.