These are pretty old - and although the Ubuntu version claims to install (Linux Mint64 17.3) the (older) 5.2.x camera firmware and newer (3.4.91) NVR firmware doesn't recognise its existence.
I've never tried on the newer camera firmware as I need to use the Oracle VirtualBox for the NVRs. DOWNLOAD PORTAL
But for Live View,not configuration, on the cameras, VLC and QuickTime seem to work OK.