You downloaded firmware for a different sub-model (e.g., XVR1B16H-4KL vs XVR1B16H). Solution: Double-check your hardware revision. Look at the sticker: DH-XVR1B16H-4KL-S2 . Search exactly that.
Disclaimer: This article is for educational purposes. Always back up your DVR configuration before updating. The author is not responsible for bricked devices. Ensure you have the legal right to modify the firmware on your device. dhxvr1b16h firmware free