Ahhh ok, now we understand each other
My guess would be, that you got the Time Out error, because of a issue with the NVR connecting to the internet. It cannot reach the servers from Dahua. I would not recommend it anyways, and always do the firmware upgrades manually / locally. Not having the NVR connected to the internet.
When i do a firmware upgrade of one of my camera's, i do this from within the NVR. As i showed in the picture above. Except on your NVR you find that menu next to the Registration tab.
Or i just do it the hard way, and pull the network cable of the camera to be upgraded, power it via a DC supply, hook it up to a laptop, and do the upgrade via the web interface of the camera (without the NVR inbetween)
This way i've had no problems upgrading the firmwares. If i do it thru the NVR on the camera's web interface, then mostly it will fail.