I've been a computer geek since the Mac Plus and IBM PC junior, so feel free to use big words on the computer side. I'm new to the Nikon, as a friend who moved to assisted living gave me a Coolpix E990 and an E8700, and an awesome Manfrotto tripod. (He was a pioneer in the 360 field.)
When I plug in the USB data cable to my Coolpix E990, I get the tiny icon of the computer and the little marching ants on the control panel. Fine so far, but that's it, and the ants never stop (I took just one photo). The PDF version of the manual doesn't say what should happen on the computer, but I half expected it to work like a typical thumb drive: It just mounts as a volume. The Disk Utility app does not see the camera as a mounted volume.
I also downloaded the Nikon ViewNZ 2 software, since it's free. Its DMG volume has only a Welcome.app. When it launches (after removing the unknown-developer blocking), the screen flashes for maybe a quarter-second, and that's it. I'm running a MacBook Pro and Catalina 10.15.5.
I suppose I could buy an adapter to use the memory card, but since I have the cable, I'd like to get it working.
Any ideas?