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Monday, October 26th, 2015 7:25 PM

Security Certificate Expiration on HTC 8X (PM23300)

On Monday, October 19, 2015, a security certificate on the Microsoft authentication servers was updated. This certificate change causes customers using AT&T HTC 8X devices to be unable to log into and use a variety of Microsoft services. This severely impacts the device experience.


How does that affect you?

  • The HTC 8X device uses a security certificate named SHA-1 (pronounced “Shaw One”) to authenticate you on Microsoft services, such as Outlook, OneDrive, Xbox, Windows Store, etc.
  • This security certificate has known vulnerabilities and is being replaced across the industry.
  • Microsoft began replacing this certificate in their authentication servers on Monday, October 19, 2015.
  • After this certificate is replaced, the HTC 8X device can no longer use Microsoft services, such as Outlook, OneDrive, Xbox, Skype, etc.
  • Because of the age of the device operating system, the only way to change the HTC8X security certificate is to change the device firmware using the Microsoft Device Recovery Tool.
    • It cannot be changed by an Over the Air (OTA) update.
  • This process should take about 45 minutes to complete.


What do you need do?

  1. Review “How does that affect you?” section above.
  2. Create a backup as the device will be wiped when using the Microsoft Device Recovery Tool.
  3. Charge your device to at least 50 percent before attempting to resolve.
  4. Head over to for troubleshooting steps.
  5. If you would like a walk-through or additional support, please contact Microsoft support at 888-665-4228.

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1 Message

9 years ago

This program does not work. I have spoken to representatives from ATT, HTC, and Microsoft and all of them have pointed me to speak to each other but no one can tell me how to fix this. An HTC representative said that HTC and Microsoft haven't been able to figure out why this issue is occurring with HTC 8X. A perfectly functioning phone that isn't damaged no longer works. It feels as if my phone has been deemed mediocre and is being phased out. I have been a WP user since the very first PDA came out and I thought I could hold on until the end. I am done with WP. Over and over again WP users have been shortchanged in some form of fashion. I am finally fed up. I was a die hard fan who just died really hard.

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