Windows Phone 8.1 build 12075

Windows Phone 8.1 build 12075 is a build of Windows Phone 8.1. It was leaked on 2020-01-03 by gus33000. It is based on Windows 8.1 build 9379.

WARNING
Extremely Stern Warning: The NTFS driver in this build has multiple critical and extremely severe bugs.

Installing this build has a 75 percent chance of completely wiping the eMMC of the device you install it on.

Even if you do manage to install it, this build can and, most likely, will corrupt the NTFS file descriptor randomly, making it look as if there are 0 files on the drive.

This build is also capable of writing garbage data at a random location on the eMMC if boot fails. This includes the UEFI and bootloader, You WILL need to re-flash the eMMC if any of these things happen. Backup the eMMC before you install this build and exercise extreme caution when doing anything with this build.

Particularities
This build of Windows Phone 8.1 incorporates many features rumored at the time, such as:


 * A Notification center application
 * The ability to sort the application list by most used
 * A couple new versions of some system apps marked with a z in front of them
 * An early version of Cortana, Microsoft's own Digital Assistant

Sadly the early version of Cortana can not be used anymore nor seen because the servers for Microsoft Account login used by this build have been taken offline.