Google photos refused to back up via mobile Hotspot
I ran into a problem making my father’s phone sync pictures to Google photos, it simply refused to run, just saying “uploading photo 1 out of 489”.
After messing around on my own I started searching the net and finally found this rather obscure explanation, which fixed it for me. Apparently the phone realized it was running over a mobile Hotspot and refused to run because of it. See this blog post to fix it.
http://www.mihneadb.net/unblocking-google-photos-autobackup/