If you need to repair or restore a lost IMEI after a legitimate firmware flash on a Spreadtrum (now Unisoc) device, I recommend using official service tools through authorized service centers or legitimate software provided by the device manufacturer. For development or repair work, consider using the original Spreadtrum upgrade and download tools from verified sources, and always follow local laws regarding device identifiers.
: Ensure you have the Unisoc/SPD USB drivers installed on your PC. You can verify this in the Device Manager; a successful connection usually appears as an "SPD U2S/Diag" COM port. spreadtrum imei tool v41 patched