I subscribed to professional edition. The files in the Google Photos drive folders are all ZERO. I have left the program to run for hours and still every file has ZERO size, and cannot be opened.
The same happens to me!!!
Google Photos API does provide the file size information after reading media itself.
It is the reason why the size of a file is displayed ZERO. If you display/play a media with a viewer, Google provide the size information. And you can see in the File Explorer.
I think this has something to do with Google Pictures website, and when you have created Albums in there. I noticed I too was getting a file size of zero on some of the pictures. I did a search on the whole new Photo Folder that I was trying to make on my PC of a picture size zero file name, and up popped 2 of the same files. The zero file one along with the one in the downloaded Album in which I could actually see the picture. Now, on the Google Pictures site, when you make an Album and put pictures in there, they are still located under the All Photos tab. I think this is what the problem is, somehow there is a size zero placeholder in the All Photos file and the real picture file is moved to Album folder.
What I did was (and I know it’s gonna be a PitA later making new Albums on my PC), was to delete all of the Albums off of the Google Pictures site (it will still keep all of your photos), and the PC size zero folders, then disconnected the RaiDrive for a couple of minutes. After reconnecting, I first checked to see it the RaiDrive Album folder was empty and it was, so I started to recopy the needed files to my PC, and all was working as it should. I just did the zero size files, but if you don’t want it to be too confusing you could delete all of the new PC files and start completely over. It’s up to you.
Hope this helps/works for others having the same problem.