Wrong firmware for your hardware version. Fix: Double-check the hardware revision in System Info . Contact support with that exact revision number.
Unlike PCs, you don’t need to update every month. Follow this schedule: dvr-5608l-n firmware update
file from the official support site, copying it to a FAT32-formatted USB drive, and selecting "Upgrade" in the System Maintenance Feature Enhancements : Firmware updates for this series typically address H.265+ compression efficiency Wrong firmware for your hardware version