Microsoft apologizes for 'unintentional' Windows 10 builds, offers recovery tips
Yesterday, Microsoft pushed out Windows 10 Insider Preview Build 16212 for PC and Mobile to users on the Fast, Slow, and Release Preview rings and the Retail version. Unfortunately the buggy build wasn’t intended to go out, causing problems for anyone who installed it.
Apologizing for the "inconvenience", Windows Insider chief Dona Sarkar explains it "happened because an inadvertent deployment to the engineering system that controls which builds/which rings to push out to insiders." While Microsoft was quick to pull the update, it was too late for some.
Microsoft says that its analysis "shows only a small portion of folks got these builds" and offers the following tips for those affected:
If you received this build (from RS_EDGE_CASE) on your PC: Please be aware that this build was never intended to go out to Windows Insiders and may include issues that impact usability of your PC -- more so than the normal builds we give you. You can either sit tight and wait for us to publish a newer build to you or you can roll-back to the previous build via Settings > Update & security > Recovery. And check your Windows Insider Program settings.
If you received this build (from RS_IoT) on Mobile: This build will not install on your device. If you installed this build, your device will be stuck in a reboot loop and the only way to recover is to use the Windows Device Recovery Tool and re-flash. After re-flashing, you can join the Windows Insider Program again on your device and choose your ring and be back on the right update path.
If your device has downloaded this build but has not installed the build (you see either a "Install" or "Restart now”" button under Phone update) -- you will have to do a device reset via Settings > System > About (Do a backup via Settings > Update & security > Backup FIRST) and then check your Windows Insider Program settings to ensure you’re on the right ring.
Remember, if you have installed the build on PC you only have 10 days to roll it back, and this won’t work if you’ve used Windows Disk Cleanup to free up space.
There is some good news for non-Windows Insiders who saw the build. Microsoft says "these builds will not install on devices that are not joined to the Windows Insider Program (a.k.a. 'retail')."