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Duo Multi Factor Authentication Self-Help

Common Issues with Duo Mobile & Troubleshooting Solutions

For any issues not listed here, contact the IT Help Center. 

  • I have a new phone and need to reactivate Duo Mobile. 

  • I have stopped receiving push notifications on Duo Mobile. 

  • I lost my phone and my number changed. 

  • My hardware token stopped working. 

  • I am running iOS 10 and I am not able to install the current version of Duo Mobile from the App Store on my device. 

  • I am using Microsoft Internet Explorer and the Duo Prompt does not display correctly. 

Other Issues 

You can check out Duo’s knowledge base for further assistance or contact the IT Help Center.

If you lost your phone and you have the same number as your previous phone, follow these steps:

  1. Log into the CSUN portal. If you are already logged in, log into the CSUN portal using a private browser.

    Wait for the Duo prompt to appear, then select Other options at the bottom of the Duo prompt.

  1. At the bottom of the list of other options to log in, select Manage devices.

  1. Verify your identity via phone call or SMS

  1. Select I have a new phone, then select Get Started 

  1. Confirm that your phone number listed is correct, then select Send me a passcode or select the other option Or call my phone

  1. Enter the two-factor authentication passcode or answer the phone 

  1. Download Duo Mobile from the App Store or Google Play on your mobile device

  2. Open up the Duo Mobile app on your phone and select Add

  3. Use QR code

  4. Scan the QR code from your computer

  5. If you would prefer to send an activation link to yourself, enter your email address, then open the link on your mobile device to activate Duo Mobile. 

    Once you have finished adding your new phone, select Back to login to continue logging into the CSUN portal.

If you cannot log into Duo at all, contact the IT Help Center. 

You may not be receiving push notifications from Duo if there are network connectivity issues.  

Your phone may have trouble determining whether to use Wi-Fi or cellular data when checking for push notifications. 

To solve these issues:  

  • Try putting your phone on airplane mode and turning it off again. 

  • Turn off the Wi-Fi connection and use the cellular data connection. 

If you lost your phone and your number changed from your previous phone, contact the IT Help Center. 

If your token stops working or if you can't log in with the passcodes it generates, contact the IT Help Center.  

Your token can get "out of sync" if the button is pressed too many times in a row and the generated passcodes aren't used for login. In some cases, this can happen by accident if the token is stored next to other objects in a pocket, backpack, etc. You will be asked to generate three passcodes in a row and attempt to resynchronize the token.

The minimum supported operating system version for Duo Mobile 3.29.0 and above is iOS 11. 

iOS 10 users may download the last Duo Mobile version compatible with that iOS version (3.28.1) via Apple's TestFlight program. 

  1. You'll need to install the Apple TestFlight application on your device. 

  1. Once you have TestFlight installed, tap this link and then tap Install to install Duo Mobile 3.28.1 on your iOS 10 device. 

Contact the IT Help Center if further assistance is required.

For best results we do not recommend using Internet Explorer's Compatibility View with Duo authentication. You may be able to turn off Compatibility View yourself. 

From the Address bar: 

If the Compatibility View button displays in the address bar to the right of the page address, you can select the button to exit Compatibility mode. 

From the Internet Explorer Tools Menu: 

In the Internet Explorer browser window press the Alt key to display the menu bar. Navigate to Tools → Compatibility View settings and make one or more of the following changes: 

  • Remove the website where you use Duo authentication from the websites you've added to Compatibility View.

  • Uncheck the Display all websites in Compatibility View option if present and enabled. 

  • Uncheck the Display intranet sites in Compatibility View option. 

Select the Close button to save the change.

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