EXTERNAL: The user does not have access to service account "default"
It happened on my project this morning. Disabling the Container Engine API and enabling it again should resolve the issue.
- Basically this happens when you delete the "Compute Engine default service account".
- Disabling the Container Engine API and enabling it again will create the new default service account for you with "Compute Engine default service account" name and you should be able to create new container cluster.