The problem could be some change in camera support in the Photos app, which seems unlikely, or the USB cable for your camera could be bad. I have always avoided directly connecting my cameras to my computer because there is more potential for something to go wrong with a file transfer.
If your camera uses SD cards, you could try the built-in SD card reader on your MacBook Pro; but my suggestion would be to just buy a USB card reader. They are usually under $15, and a replacement cable for your camera is probably more expensive, and probably not much use if/when you get a different camera. I have a reader from Plugable that has been very reliable. You can find it on Amazon.
If Photos doesn't launch when the card mounts, you should be able to just drag and drop from the card to your computer. I have never used Photos, so I don't know what would be involved in getting them into Photos if you transfer them using the Finder.