Since the file flash-all-lock.bat is missing, you cannot use the option that requires it. Instead, you should flash the ROM without locking the bootloader.
Extremely low. The dummy file is never executed; it merely satisfies the file existence check. mi flash error cannot find file flash-all-lock.bat
The fix is to find a missing file—it’s to change how you flash or update your tool. Since the file flash-all-lock