See how 2 pictures are selected, there is a black diamond in the right upper corner. I can not get rid of LR picking another photo is I deselect one, it picks another one. I have tried everything to stop it from selecting another picture. I have never seen the black diamond in the right upper corner. Please help:)
Are you in "Compare" mode. The 'diamonds' appear on filmstrip thumbnails in Compare mode.
Try pressing the 'C' key.
Thank you soooooo much, it worked. I was going crazy trying to figure out what I did. Bless you.