The is not a death sentence for your device. It is primarily a protective mechanism gone awry, triggered by version mismatches, corrupt backups, or improper settings. By systematically changing the NV operation mode, switching tool versions, or (as a last resort) formatting the NV region, you can successfully flash your Unisoc/Spreadtrum device.
The "BKF NV" error acts as a safeguard mechanism. In 90% of standard repair cases, (Method A) resolves the error and restores the device to working order without risking the device's network calibration data. spd flash tool bkf nv error
tab. Uncheck all items related to "NV" or "Calibration" (e.g., PhaseCheck The is not a death sentence for your device