Simon is correct - any changes in any data entity that is passed between the datastore and the client will cause this problem. And it's not just the login issue. An application may be updated when a user is already logged in and using the application. The next call to the server may fail if it involves an object that fails to deserialize.
Our solution was to raise a NewVersionException when we detect a call from an old client. We make this determination before we process the request, so we avoid running into a server error. When this exception reaches the client, we inform the user that a new version of the app is available, and ask them to reload the page. You don't need to add a version number to the User model. We store client version number in a session attribute. Then we compare it to SystemProperty. applicationVersion.get(). Andrei Volgin www.spiraluniverse.com -- 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?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
