ERR_SSL_PROTOCOL_ERROR

This error means the browser couldn't establish a secure connection because the website's SSL certificate is invalid, misconfigured, or cannot be verified.

In Chrome, you may see this displayed as ERR_PROTOCOL_ERROR — a more generic message that usually points to the same underlying SSL issue.

Common causes

• The SSL/TLS certificate is missing, expired, or set up incorrectly
• A protocol mismatch between the browser and server
• Browser extensions interfering with the secure request

How to fix it

On OS Cloud, this error is often caused by an SSL certificate that has not been requested, does not cover every hostname in use or has expired. Follow Request an SSL certificate to check the configuration and request a certificate.

Note: If you're on a managed cloud plan and your website is moved to another server, this issue is resolved automatically.