The top 5 reasons why Google Hangouts never works
1. Hangouts doesn't work in Internet Explorer from the Windows 8 Start screen
If you're using the Start screen to launch Internet Explorer, you may find that Hangouts simply doesn't work. That's because Hangouts requires a plug-in to operate on IE, and the full-screen, Metro-style version of IE doesn't allow any plug-ins at all. To work around this, you have a couple of choices. You can run IE in Desktop mode by launching it from the desktop instead of the Start screen, and then install Hangouts, or you can simply switch to another browser.
2. If you run Hangouts on multiple devices, Hangouts sends notifications to everything that's running, causing alert overload
If you have Hangouts open on your desktop and your phone simultaneously, notifications will pop up on both devices, even if you aren't actively engaged with one of them.
This is unfortunately a known issue with Hangouts. It's a pain for some users, while other users actually prefer it to work this way.
If you're getting too many notifications, a few solutions are available. First, you can sign out of Hangouts on devices or browsers form which you don't want notifications, or close the app altogether.
On Android devices, you have a few more options. You can use Menu > Snooze notifications to suspend alerts on that device. Notifications can also be suspended indefinitely on a per-user basis by selecting the gear icon in a Hangout window and unchecking the Notifications box there.
3. Photos sent via Hangouts over MMS taken in portrait mode automatically rotate and turn into landscape photos
This is a specific issue related to Hangouts on certain Android phones when pictures are sent over MMS. Many users report that the problem is erratic and that clearing application data from the Android Applications Manager may help, at least some of the time.
The more reliable solution is not to use the camera within Hangouts to snap photos, but to take pictures separately, using the standard Android camera. When portrait photos are attached from your photo library, they seem to come through with the proper rotation intact.
4. Video calls don't work
While there are many potential reasons that Hangouts won't initiate a video call, here are a few of the most common troubleshooting tips.
First, the Chrome browser doesn't require a plug-in for Hangouts to work... unless your company uses Google Apps, in which case you will still have to install the Hangouts plug-in to make video calls. It's also a good idea to install the Hangouts Chrome app, which adds Hangouts to the Chrome App Launcher, where you can initiate a new video call.
Note that Hangouts does not support a handful of webcams, microphones, and audio devices. Presuming this is not your issue, make sure the correct audio gear is selected within Hangout's settings menu. To find this menu, initiate a new video, then click the gear icon.Hangouts may work better if you select specific devices for each of the three options instead of "Default."
Finally, in general, restarting your browser and/or your computer is also a good cure-all for any video-related problem within Hangouts.
5. The Hangouts Browser plug-in won't install (or disappears)
Can't install the Hangouts plug-in First, make sure you aren't running 64-bit Internet Explorer, as the plug-in is not supported on this browser. If you're using Chrome, check chrome://plugins/ to see if the Google Talk plug-in is installed and enabled. (The name is a remnant of Hangouts' prior incarnation.)
You can also try uninstalling this plug-in (instructions can be found here) and reinstalling it. Remember that the Hangouts app is different from the Hangouts plug-in. (You don't need the former, but all browsers except Chrome require the latter.) If the Hangouts app has vanished from Chrome, simply re-enable it by re-downloading it from the Chrome Web Store.