By using the site I accept the Privacy Policy and Terms of Service
If 6.2.55 cannot fetch firmware, download the .nb0 firmware file manually from LumiaFirmware and use the “Offline mode” (not officially supported but doable via folder replacement).
— End of monograph layout —
If you have a Lumia device running Windows Phone 8.0/8.1 or Windows 10, you should use the Windows Device Recovery Tool (WDRT) instead of NSRT. System Requirements for Your PC