The SSL certificate that lets your website load over HTTPS has expired or soon will. Once it lapses, browsers show visitors a full-page security warning, and most of them leave.
What it means
Certificates are valid for a limited time, often 90 days, and must be renewed before they run out. Most hosts renew them automatically, so this issue usually means automatic renewal has stopped working.
What triggers it
SSL certificate monitoring reads the certificate your website serves once a week, and daily within eight days of expiry. The issue appears 14 days before expiry as High, and turns Critical with a day or less left. Owners and admins are emailed a week before, a day before and once it has expired.
Common causes
- Automatic renewal failing, often because the domain’s DNS changed or a firewall blocks the renewal check.
- A certificate bought by hand that nobody renewed.
- A CDN, proxy or load balancer still serving an old certificate after the server got a new one.
How to fix it
- Renew or reissue the certificate in your hosting panel or CDN; most hosts and Cloudflare offer free ones that renew themselves.
- If it should have renewed automatically, find out why it didn’t, so it doesn’t happen again.
- Make sure the new certificate is installed everywhere the website is served, then check the padlock in your browser.
When it clears
It clears at the next check that finds a certificate with more than 14 days left. Close to expiry the check runs daily, so a renewal is usually noticed within a day.