My custom domain is showing SSL Mismatch error

Posted on October 6, 2020

Senior Software Engineer II

After I added a custom domain to my app, when I visit that domain it shows me a SSL version or cipher mismatch error.

This site can’t provide a secure my-website.com uses an unsupported protocol.
ERR_SSL_VERSION_OR_CIPHER_MISMATCH

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Jon Friesen

October 6, 2020

Accepted Answer

This can happen when the CNAME isn’t yet configured before adding it to app. Our TLS certificate issuer caches the NXDOMAIN (not found) DNS record, and the TLS certificate issuing is delayed. Normally it resolves automatically once the NXDOMAIN cache expires in about 30 minutes.

Trunksome

October 15, 2020

I seem to have the same issue. What I want to do is point a subdomain to my DO app.

Added a new app (the feature is great btw!), deployed it, and then added a new CNAME entry to my DO networking (DNS is managed by DO). Then getting “ERR_SSL_VERSION_OR_CIPHER_MISMATCH”.

What did I do wrong here?