If you are using firmware version is lower than the Y1.0.14.

When you want to upgrade to the newest version, You have to update the bridge FW first.

Please download your NVR machine type's bridge firmware.

Then open the NVR webpage, Enter the System ¡÷ System Update page.

And use the "Firmware Upgrade" Function to update your NVR machine.
 
When machine is updating, Please do not remove the power.

After the update progress, NVR mahine will be auto reboot.