After upgraded to 4.2, I can't login to my dashboard anymore. It is always redirect to this url http://www.xxx.com/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F and show notice of "No Update Required". See screenshot: http://prntscr.com/6xganm

When I click "Continue" it just go back to the homepage of my site, and I can't login at all. Still working with my host, and just wondering if anyone has seen this kind of message.

Regards,
Joseph