Duo / Resolve Duo prompt display issues

Objective

• To provide instruction on resolving issues with the Duo prompt not displaying correctly

Environment

• 312306: Duo Security Two-factor Authentication
• Apple IOS / Mobile Devices / Phone / Tablet
• Mac OS X / OSX / Computer

Resolution 

While attempting to log in to a Duo-protected application, the Duo prompt may not display correctly or give one of the following errors, which is a result of content restrictions being enabled on the device. 

• The Traditional Duo Prompt may display as an empty gray box or give the message "You cannot browse this page at 'duo.com' because it is restricted"
• The Duo Universal Prompt may display a blank screen or give the message "This site can't be reached"

For macOS 10.15 or higher

1. Open System Preferences
2. Navigate to Screen Time > Preferences > Content & Privacy
3. Add duosecurity.com to the Allowed Websites Only list
   • If you prefer to remove all content restrictions, set any Web Content restrictions to Unrestricted access

For iOS 11 or older

1. Navigate to Settings > General > Restrictions > Websites
2. Add duosecurity.com to the allowed sites list
   • If you prefer to remove all content restrictions, uncheck Limit Adult Content

For iOS 12 or newer

1. Navigate to Settings > Screen Time > Content & Privacy Restrictions > Content Restrictions > Web Content
2. Add duosecurity.com to the allowed sites list
   • If you prefer to remove all content restrictions, uncheck Limit Adult Websites