Hello Catherine! Thank you for your question. I will be assisting you today.
I'm sorry about the issue. Please try each of the followings until it works:On the phone:- To delete one photo at a time, open the
Photos app > touch the thumbnail of the photo you wish to delete to open it >
trash icon.- To delete multiple photos at once, open the
Photos app > touch the
menu icon/button > Select... > the thumbnails of the photos you wish to delete to select them >
- And/or Open the
Google+ app > touch the
menu icon/button > Settings > Auto Backup , then turn off auto backup.
- If that does not work, on a computer, go to the website https://plus.google.com/, then sign in your google/gmail address that is associated with your phone, then lace your cursor over the Google+ Home menu near the top left corner > Click
Photos > More >Auto Backup (or you can go directly the website below:https://plus.google.com/u/0/photos/search/%23AutoBackup), then checkmark icon in the top left corner of each photo you wish to delete > Delete.If needed, you go to Apps -> Settings on the phone, then go to Privacy or Backup and reset, etc., and then do a factory reset.
More info if you need:
Please click on the Reply to Expert tab below, and reply back to me, so I can help further if there is still any issue. Thank you,