Windows 10 build 16212 breaks PCs and phones, roll back now

By: Madeleine Dean
2 minute read

Microsoft accidentally rolled out Windows 10 build 16212 for both PC and Mobile. The unfortunate Insiders who installed this build on their devices regret their decision now after realizing how buggy it is. Insiders report that this OS version sends their devices into infinite reboot loops, preventing them from actually using their devices:

My two fast-ring Lumia phones (Lumia 950 XL, and Lumia 950 XL DS) have been running build 10.0.15215.0 for a while,  and have both successfully downloaded a new preview build: 16212.1001.rs_iot.170531-1800 (UUP-CTv2). A IOT build for the phone? Strange.

One phone has just rebooted, but is stuck in an endless reboot loop: it displays the colored flag Microsoft logo for a short time, then reboots, …

The second phone is asking for the required reboot to start the update process but I I’m hesitant to push the “Restart now” button after the experience with the first phone.  Anyone else seeing this strange build and behavior?

Microsoft says this build release was a mistake

Dona Sarkar already published a lengthy post on Microsoft’s official Windows Insider blog explaining that build 16212 is actually an internal branch build that was accidentally released due to a system error. The good news is that the Insider Team was quick to revert the deployment and blocked this build from going out to more people.

How to fix the bugs caused by Windows 10 build 16212

If you already installed build 16212 on your PC, you now have two options:

  1. Sit tight and wait for Microsoft to roll out a new build — hopefully, a more stable one
  2. Roll-back to the previous build via Settings > Update & security > Recovery. Keep in mind that you have up to 10 days to roll-back. This method will only work if you did not perform any Disk Cleanup action to remove your previous Windows installation.

How to fix endless reboot loops on Windows 10 Mobile

Build 16212 will send your phone into endless reboot loops. The only way to recover is to use the Windows Device Recovery Tool and re-flash. You can then join the Windows Insider Program again.

If your device has downloaded this build but has not yet installed it, simply reset your phone via Settings > System > About. Don’t forget to do a backup first via Settings > Update & security > Backup.


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