If you are still using v37 or v38, update to v41 immediately . The stability improvements for newer Unisoc Android 13 devices are significant. It’s not the prettiest software, but it remains the industry standard for baseband repair on Spreadtrum chipsets.
If you get "Write Failed," try switching to Meta Mode (select "Connect via META" in settings) or use the Backup/Restore method: first backup existing IMEI, modify the backup file, then restore. spreadtrum imei tool v41 updated