I used to have permissions to remove a custom domain on Google App Engine or upload a new SSL certificate.
However, one day the SSL certificate was expired and I could not upload a new SSL certificate and got the following warning message.
"You do not have sufficient permissions to view this page".
When I remove this custom domain and also got the following warning message.
"All domains mapped to this application are shown below. Only owners of a domain may remove one of its mappings."
I am the owner of managing the domain name group in Google Cloud DNS and project.
Any ideas to solve this issue.
I solved this problem. I don’t know why this suddenly happened. The solution was to remove the app engine and create it again and setup the custom domain. App engine only allows someone who created this app engine and domain name can manage domain names or update ssl certificates.
Moreover, Google now has a new feature to provide auto-renewed ssl certificates for app engine.