Microsoft on Thursday, 1 June apologised for releasing internal Windows 10 builds for PC and mobile to Insiders "accidentally". The company also said that it would not be releasing new builds this week.
In a posting on Windows Blog, Dona Sarkar, software engineer at Windows and Devices Group explained the rollout of the builds were unintentional and this happened "because an inadvertent deployment to the engineering system that controls which builds / which rings to push out to insiders."
The company was quickly reverted the deployment of the internal Windows 10 builds, and put blocks to stop the builds from seeding for more Windows Insiders. While it did not reveal how many people were affected but said only a "small portion" of users got these builds.
Those Insiders, who received the internal build on PC, note that they include issues which impact the usability of the PC. You may either wait until Microsoft publishes the next build or consider rolling back to previous build.
To revert to an earlier version go to Settings>> Update & Security>> Recovery. You have up to 10 days to roll-back. Also, keep in mind this process will work if you did not do Disk Cleanup to remove the previous build.
For mobile devices
If you have installed this build, your Windows 10 Mobile device will get stuck in reboot loop. You can recover the device by using the Windows Device Recovery Tool and re-flash. After that you can join the Windows Insider Programme again and choose any ring.
If you have downloaded the build and have not installed, you will need to do a reset by going to Settings>> Systems>> About and then check your Insider programme settings to ensure you are on the right ring. Do not forget to create a backup of the phone before performing a device reset.