Same problem. Intermittent, but for the last few days doesn't work. I
have attached the output of numerous cli commands to help
troubleshooting. When I choose PTP mode instead of MTP mode Shotwell
fires up and can receive photos and videos.
One thought is that USB cables are notorious for wearing
Public bug reported:
This affects an installation of Ubuntu 14.04 on a Lenovo laptop.
When applications like nautilus or Bluefish are connected to a remote fileshare
using sftp (ssh) via a lan connection, if the connection is lost and
re-established the old process seems to hang blocking attempt