The service known as Gchat—a.k.a. Google Talk or Google Hangout—is currently down for a lot of user all over the world. That means many people are having trouble sending and receiving messages over Gchat, and in the case of my account, I can’t even see who’s online.
The Gchat outage is joined by an outage in Google Drive for some users, and there hasn’t yet been word from Google about what’s causing the problem or when it might be solved. So you might want to take this disruption as an excuse to go outside and take a walk or something (or maybe catch up on Words With Friends).
You may also want to keep an eye on Google’s official blog here in the event that they release a statement on the current Gchat outage. Or you could just stay parked in front of your Gchat window, waiting patiently.