On snapchat when I move a pic from camera roll to my eyes only it says toggle private status failed?

First you have to move the photo in your phone's gallery FROM the folder it is now TO the 'snapchat' folder , then go to snapchat's settings > memories > Import Snaps From Camera Roll , import the photo through there , finally you are able to move the photo from your memories (on snapchat app) to My Eyes Only.