Update: after killing gvfs-photo2-volume-monitor and setting IsNative=true in /usr/share/gvfs/remote-volume-monitors/gphoto2.monitor I can download the preview images but importing still fails with the error. My previous comment was a bit too overhasty.
Update: after killing gvfs-photo2- volume- monitor and setting IsNative=true in /usr/share/ gvfs/remote- volume- monitors/ gphoto2. monitor I can download the preview images but importing still fails with the error. My previous comment was a bit too overhasty.