Error 1016 - app offline


We have an app that suddenly went offline with the Error 1016.
The app is hosted at Heroku, it is definitely working fine at and DNS records are correctly pointing where they should (haven’t been changed).

Any idea how to bring the app back online?


Are you using “A”, or “CNAME” records? A 1016 generally means it’s pointing to an IP address that’s not allowed to respond to your hostname.

CNAME. For years and it worked fine until now.

I have other apps with exactly the same configuration. They are working fine without any issues.

It’s quite possible that whatever you’re pointing it to is no longer configured for that hostname. I suggest you set that DNS entry (CNAME) to :grey: DNS Only and see how it behaves. It takes 5 minutes for that change to take effect. If it’s still broken, you’ll have to contact the destination host to find out why your CNAME no longer works.

I made this change. Let’s see in a few minutes. I am not sure what you mean though. The CNAME is pointing a name to a heroku app The is working fine when I open it.

The app may be working on its own URL, but if it’s not configured to answer to as well, that would cause an error.

You are right I think. I removed the domains at Heroku, added them again, and then new targets were displayed. Once I updated those at Cloudflare, the name was resolved again. So it was a Heroku issue.
Thank you for your help!

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Hmm… the error is back.

How do i set it to DNS Only?

Click on the DNS entry to get it into Edit mode, then click on the :orange: to toggle it to :grey:.

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