I got this error when logging in 4 accounts. It works on logging in 3 accounts.
We can not control the number of accounts a user login at the same time. I think it is a critical bug in the implementation of Google. Conclusion, Users API is not usable. The only way is to use OAuth. -- 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 http://groups.google.com/group/google-appengine. For more options, visit https://groups.google.com/groups/opt_out.
