I recently upgraded my Linux Mint from 17.3 to 18 so that I could move to the more recent version of Kdenlive V15.13.12 Still not the latest but better than the default software manager version.

After all was said and done I plugged in my GoPro to retrieve some clips I had done. It displayed the directories but they were empty.
I searched all over trying to find the solution and finally found a post on it at http://bernaerts.dyndns.org/linux/74-ubuntu/347-ubuntu-xenial-gopro-usb-access-bug

If this helps you then send him a thank you, his link is at the bottom of his page.