As you will find when you continue to research, the results will be variable. The process is supposed to automatically take a backup of your device before starting and restore from that backup when the process succeeds. But, this is, as I say, how it is "supposed" to work. There is no substitute for good manual backup processes to protect your critical user data. You can find full instructions for backups via the link in my auto-sig on this post.
Occam's Razor nearly always applies when troubleshooting technology issues!
New to the Community? Click here and also here for helpful guidance. Also please click here for additional helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions. If anyone has been helpful to you, please show your appreciation by clicking the button. Need a reference to BB10 OS/SR versions? Click here. Need a specific BB10 AutoLoader? Send me a private message.