Unable to add Cloud NAT Gateway to existing Cloud Router

[benjaminos]

Hey,

I have an existing Cloud Router with a couple of BGP sessions associated, and I'd like to add a Cloud NAT Gateway to it. From what I can tell, this should be possible, but both via the web UI and the CLI, I get an error:

$ gcloud --project my-project compute routers nats create my-nat-gateway --router existing-cloud-router --nat-external-ip-pool my-static-ip --nat-all-subnet-ip-ranges --enable-logging --region europe-west1
ERROR: (gcloud.compute.routers.nats.create) HTTPError 400: Updating multiple Router features is currently unsupported.

 I get no hits for this on Google, so I'm wondering if the Cloud Router has pending changes somewhere that I can't see (no clues from describing it via the CLI), it's otherwise broken, or something along those lines.

Has anyone come across this before?

Thanks,

Ben

[benjaminos]

Just as an update, I've tried to do the same thing on a different Cloud Router in a different project altogether, and I get the same error message. I'm assuming that means that the router itself isn't at fault, but I'm still no closer to figuring out the problem 🤔