Google had a massive outage today, lasting about 30 minutes and impacted Gmail, Google+, Google Calendar, and Google Documents. It’s uncommon that Google has such a widespread outage with their services. The Official Google Blog noted:
For about 10 percent of users, the problem persisted for as much as 30 minutes longer. Whether the effect was brief or lasted the better part of an hour, please accept our apologies—we strive to make all of Google’s services available and fast for you, all the time, and we missed the mark today.
Google blamed the login issue on a product malfunction or bug keeping users from logging into popular services like Gmail and Google Calendar. Gmail login issues were met with the error message shown above.