I bought a newer version of Dahua IP cameras and after setting the camera through the web browser and connecting to my older dahua NVR, I got the “conf.LoginErrorNo-20” error. The camera works on all web broweser like firefox, google and microsoft end web interface and SmartPSS but immedialtely i connect the camera to the nvr, I got “conf.LoginErrorNo-20” error on the screen as shown below:

This turned out to be a compatibility issue. I had an older version of NVR and I tried to add a newer camera but the NVR could not recognize the IP camera and would display the above error beside the fact that the NVR could assign an IP address to the camera. I updated the NVR firmware and changed the camera and added the camera to the NVR using ONVIF method. This method works by adding the camera as an ONVIF device.