cURL error 60: SSL certificate problem means WordPress can't verify the SSL certificate of a site it's connecting to, for example when checking for updates or contacting a payment provider.
Fixes
- Update WordPress from Dashboard › Updates. Each release includes an up-to-date list of trusted certificate authorities.
- Update the plugin showing the error, as some ship their own outdated certificate files.
- Check your own SSL certificate if the error mentions your own domain (for example in Site Health loopback tests). Make sure it's valid in SSL/TLS Status in cPanel.
- Check the server time isn't wrong, which can make certificates appear invalid; raise a ticket if you suspect this.
Never "fix" this by turning off SSL verification in code; that makes connections insecure.
