MFA-Duo - Duo Prompt Display Issues on iOS and Mac OS

Mac OS and iOS have content restrictions that may cause issues with the way the Duo Prompt renders.

Scenario 1

Users may be presented with a "403: Forbidden" error as shown in the screenshot below:

403 Forbidden error


Have the user check and make sure that their time zone/clock settings are set automatically on their device.


  1. Navigate to Settings > General > Date & Time and make sure "Set Automatically" is toggled on.

Mac OS

  1. Navigate to the Apple Menu > System Settings > General (in the sidebar) > Date & Time and turn on "Set time and date automatically."

Scenario 2

Users may be presented with the error "This site can't be reached" and in some other cases may only see a blank screen.

Note: This information can be found at


  • Make sure that JavaScript is enabled in Safari on your macOS or iOS device. 
  • Disable content restrictions on the device. The instructions are described below for different versions of iOS or macOS.

iOS 12 or Newer

  1. Navigate to Settings > Screen Time > Content & Privacy Restrictions > Content Restrictions > Web Content.

  2. Uncheck Limit Adult Websites to completely disable content restrictions.

    Note: If you do not want to fully disable restrictions, you can add at the bottom of the "Allowed Websites Only" list.

iOS 11 or Older

  1. Go to Settings > General > Restrictions > Websites.

  2. Uncheck Limit Adult Content to disable all content restrictions.

Mac OS 10.15 (Catalina) or Newer

  1. Open System Preferences.

  2. Navigate to Screen Time > Preferences > Content & Privacy.

  3. Set any Web Content restrictions to Unrestricted Access.

    Note: If you do not want to fully disable content restrictions, you can add in the "Customize" section of the "Allowed Websites Only" option.

Keywordscontent adult restriction block settings box blank missing iphone safari does not fit cant can't see authentication push enter passcode tablet ipad iphone not showing 403 forbidden error date time   Doc ID98163
OwnerMST SupportGroupIdentity and Access Management
Created2020-02-21 12:56:50Updated2024-02-09 16:57:20
SitesDoIT Help Desk, Identity and Access Management
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