After a recent update I was unable to login to Google Hangouts on iPhone. The app asks me for username and password and then shows a dialog with authentication error with “Remove this account” and other options. My account is a Google Apps based account and not a generic @gmail.com.

Here’s how I was able to fix it.

• Login to https://admin.google.com/AdminHome
• Click on “More Controls” at the bottom
• In the list at the bottom, click “Other Google Services”
• In “Other Google Services” click the filter icon on top left.
• Uncheck the “Show top featured services”
• Search for “Google Voice” and click on the link.
• In the “Settings for Google Voice” click the drop down under the icon and select “ON for everyone”

This should fix the login issues with Google Hangouts on iOS.