It's not where the nvr and cameras are from, it's what market they were built for. Do you possibly have an international market NVR? I don't know offhand how to tell. I vaguely remember chinese market cameras having a "cn" in the serial #, but I don't remember if that was dahua or hikvision. I also don't know if the destination market is determined by hardware or firmware. For instance, I use some chinese market cameras running international firmware hacked to ignore the market info (suggesting it's in the camera hardware), but I don't know if the nvr will see it as a chinese market or international camera.