The Pangu Team, a renowned group of security researchers from China, is famous for releasing untethered jailbreaks for iOS. The "BB10-0015" string is most closely associated with the era (targeting iOS 7.1.x).
If you have decided to fix your BB10-0015 error, follow this guide carefully. This will erase everything on your phone. Your data cannot be recovered after this process. blackberry firmware pangu bb10-0015