Android Studio Assistant: No clients were able to be added to your Firebase project

Question

When using the the new (Firebase) Assistant in Android Studio to add new services I get this error:

Firebase

No clients w

Answer 1

You can go to Credentials page of Google Cloud console and manage credentials of all your projects.

In my case, I needed to remove a credential that had caused the conflict (WARN: For caution, download it before removing it. Or just modify it).

^{If you deleted your firebase project recently (like me), see: https://stackoverflow.com/a/45270281/5318303.}

---

See this for more information or other cases: An OAuth2 client already exists for this package name and SHA-1 in another project