I can't add my camera

There is another possibility, users failed to add their IP cams.

That their IP cams could be on internet, and their routers close Ping functions.

Therefore, GVD NVR will fail to add these IP cams.

The solution is to open Ping function on these routers.

Also, if your IP cams are old, not support right ONVIF version, then pls

using RTSP protocol to add your old IP cams