This same thing appears to be happening with the new Google Photos. I’ve been using the Google+ Auto Backup on my phone for quite some time without issue. However, recently I installed the Destop Uploader and have pointed it to my 75k photos. It seemed to be chugging away nicely for almost a week. But now, nothing is getting backed up anymore. Not even on my phone.

I realize that this is a free service, but I just wish they would publish their unofficial limits some place.