Unable to scale up cluster nodes due to permissions

Problem

When trying to delete a cluster manually or during cluster node scale up or down, the operation fails with the error described below:

Required 'compute.instanceGroups.update' permission for 'projects/[name]/zones/[zone]/instanceGroups/cluster-name-nodepool-name-nodename'

Environment

• Google Kubernetes Engine

Solution

1. In Google Cloud Platform UI, Go to IAM & Admin > IAM, 
2. Look for an account named Google API Service Agent with a member project [e-mail].
3. Make sure that this account is present in the project with roles/editor permission assigned to it. 

Cause

This occurs because Google API Service Agent user account project [e-mail] is deleted from the project or is missing roles/editor permission.

This is a Google managed service account which runs internal Google processes on your behalf. And it is automatically granted the Editor role 'roles/editor' on the project.