My certificate won't renew — "cannot renew free SSL"

Free Let's Encrypt certificates are valid for 90 days, and on the Free plan renewal is manual: you re-verify your domain and re-install the certificate, the same way you did the first time. The plugin emails you 30 days before expiry.

Renewal checklist (Free plan):

1. Open SSL Zen in your WordPress admin. If your certificate is within 30 days of expiry you'll see a Renew option — click it. If the certificate has already expired, the plugin restarts from Step 1; that's normal.
2. Re-verify your domain at Step 2. If your old .well-known/acme-challenge folder still exists from last time, delete the old files first — Let's Encrypt issues a *new* verification file for every renewal, and a stale file is the most common cause of "cannot renew."
3. Verification results are valid for about 30 days. If you renew within 30 days of your last verification, Step 2 may be skipped automatically.
4. Download the three new files at Step 3 (certificate.crt, cabundle.crt, privatekey.pem) and install them replacing the old ones in your hosting panel. Installing the new certificate but keeping the old private key is the second most common failure — always replace all files together.
5. Complete Step 4 so HTTPS redirection stays active.

If renewal keeps failing: check the rate-limit article (5 identical certificates per week maximum), and confirm your site's A record still points at your server. If you'd rather never do this again, the Premium plan renews automatically every 60 days with no action from you.