Earlier today, Windows Insiders were faced with some confusion when some of Microsoft's internal Windows 10 branches were accidentally released for PC and Mobile devices. Now that some time (and the hysteria!) has settled, Dona Sarkar and the Windows Insider team have finally come up with an explanation as to why the issue occurred in the first place, while also offering advice for those who may have installed the build.
— Dona Sarkar (@donasarkar) June 2, 2017
The head of the Windows Insider team penned a note about the issue and tells Windows Insiders that this all occurred because of "an inadvertent deployment to the engineering system that controls which builds/which rings to push out to insiders." She described the issue further:
This happened because an inadvertent deployment to the engineering system that controls which builds/which rings to push out to insiders. 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.
For those who received the build on PC, Microsoft would like you to know that an install of it may "include issues that may impact the usability of your PC." Dona Sarkar offers the following advice is provided to PC users who may have installed the build.
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.
NOTE: You have up to 10 days to roll-back and this will only work if you did not do Disk Cleanup to remove your previous Windows installation.
Meanwhile, on mobile, the unintentional build will not install on your device. If you received this build, you may experience a reboot loop, and to correct the issue, you should do the following.
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.
Lastly, if you have downloaded, but not installed the unintentional build on your phone, you should heed the following advice from Dona Sarkar.
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.
Non Windows-Insiders may have also seen the unintentional build, but Dona Sarkar assures these users that the build in question will not install on devices which are not joined to the Windows Insider Program. Dona also noted that there are no more new builds to come this week, so you should be able to sort out these issues before any new builds come soon.