Solved: Google Tag Gateway "No Domains" and Google Tag Gateway "Paused"

Have you been trying to setup Google Tag Gateway, but you're seeing a message saying "There was a problem during setup" and "No domains were found for your Cloudflare account. You must have at least one active domain in Cloudflare to set up Google tag gateway"?

Or have you previously setup Google Tag Gateway, but now you're seeing a message saying it's "Paused" and "Your credentials have expired or are invalid. Reauthenticate to continue"?

Well, after a fair bit of time troubleshooting and experimenting, I've found the solution to these error messages. Let me explain what's happening...

When you first setup Google Tag Gateway, you authenticate Cloudflare to work with your GTM container. From what I can tell, when you do this, the Cloudflare account it then permanently tied to the GTM account that includes that container. Once this happens, it's not possible to authenticate the Cloudflare account to use with a container that's contained in another GTM account. 

This is how thing appear to work currently. I have reported this to Google and they're looking into the issue, so this behavior will likely change in the future, but that's what's currently happening. 

So if you want to setup Google Tag Gateway using a domain in the same Cloudflare account, you will need to setup a container in your existing GTM account. You could also try moving the domain to a new Cloudflare account, but I haven't tried this myself.

And from what I can tell, the "Paused" message appears in the original GTM container when you try to authenticate Cloudflare with another container in a separate GTM account. When I followed the steps to reauthenticate Cloudflare, I didn't encounter any issues. 

I also found that while the Google Tag Gateway settings page said it was "Paused", the container still worked correctly using the configuration from Cloudflare. You can check this using Developer Tools in your browser and viewing the 'Network' tab.

I hope that helped if you find these error messages and if you see something different or encounter another issue, please let me know!