On Thursday night, Windows users were faced with a dilemma. A build seemingly appeared out of nowhere for both PC and mobile, even to non-insiders. Some bit the bullet and installed it, resulting in bricked devices.
“#WindowsInsiders, thank you for your patience as wen debugged our #flight problem today and reached a resolution.”
She clarified further in a blog post, giving details about the fault.
“This happened because an inadvertent deployment to the engineering system that controls which builds/which rings to push out to insiders,” she said. “The team was quick to revert the deployment and put blocks in place to stop these builds from going out to more people. Our analysis shows only a small portion of folks got these builds.”
10 Days to Roll Back
Though regular Windows 10 users received a prompt to download this build, the install was prevented on non-Insider builds. If you are an Insider, you'll be familiar with the bugs it can bring, but this one is worse than usual due to the early release.
You can either stick with it and bear with the problems or roll back to the previous build. You can do that through the usual Settings>Update & Security>Recovery interface, but there a couple of limitations. Obviously, this won't work if you ran Disk Cleanup to remove the previous installation. You also only have ten days to decide before the option becomes unavailable.
Things on Windows 10 Mobile are a little more fatal. If you managed to install the build, your device will be stuck in a boot loop. The only way to fix this is to run the Windows Device Recovery Tool, re-flash, and join the Insider Program again.
If you downloaded the build but it hasn't been installed yet, you should see a restart now button in the update menu. In this case, you can backup your device and then reset via Settings>System>About.
In general, it's a major mistake on Microsoft's part, but the guidelines for Insider builds are clear. Only install them on spare devices, and look at the known issues beforehand. The Insider team will not be releasing any new builds this week, so you should have plenty of time to fix things before the next one.