Transfer files to PC

It seems like every time there is an Android update there is something I can no longer do. I would like to transfer photos taken with the Nexus 5 camera to my PC. On the pull down menu on the home page I checked USB for file transfer. The nexus 5 appears on the PC. I can click on it and the folders show. But they are all empty. The DCIM folder where I expected to see the photos shows only a thumbnails folder which is also empty. Any suggestions?
Thanks, Eva