This seems to be issue of using an old email address that no longer has permission. You can follow these StackOverflow thread 1 <https://stackoverflow.com/questions/33674606/google-api-manager-oauth-consent-screen-configuration-error> and thread 2 <https://stackoverflow.com/questions/34635543/google-developers-console-oauth-consent-screen-configuration-doesnt-save-the> that solved similar issues by clearing the history, cache, etc and/or using a different account.
If you are still affected after attempting to follow the above links, you should consider reporting the issue <https://cloud.google.com/support/docs/issue-trackers> on our Issue Tracker so proper attention can be given to it. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/8ef0c0b6-4cd7-4142-a5bd-3b41aff7a411%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
