Symptoms
When trying to access a domain using CloudFlare, the site returns the following error:
Error 526: Invalid SSL certificate.
Description
CloudFlare has a few different SSL modes, the main ones are:
- Off
- Flexible
- Full
If the Full mode is in used the site would need to have a valid SSL certificate installed via cPanel >> Home >> Security >> SSL/TLS. This happens because Full requires a valid certificate In the backend server (cPanel).
Workaround
If purchasing an SSL certificate is not an option, then the SSL mode must be changed to Flexible which encrypts the connection from the browser to Cloudflare but allows for insecure connections from CloudServer to the server.