error 400 for Google+

Jim,
Not sure what would cause a 400 error. Usually, that means there's a server denial of the request, which can be caused by firewalls or other security extensions thinking the request from Google is an automated bot trying to do 'bad things'. If you have a firewall or security features you can easily disable, I would try that.

If that doesn't work, please send us the JSON file and the URL of the page you're testing with. If you'd like to send information privately, you can use the mail icon under my name to the left to create a private message.

Thanks,
Alex