In Lightroom, why does a question mark sometimes appear the the upper right hand corner of an image? Can I delete them? Can I do a gang delete?
The photo was not found. It has even been delete or moved outside of Lightroom.
If you have delete the photo, then delete them in Lightroom as well.
If you have moved the photo, then you can click on the question mark and tell Lightroom where the photo was moved to. It will update its database and the question marks will disappear.
If neither of those is the case then the drive with the photos has either been disconnected (unplugged external drive, media not inserted) or has been connected with a different drive letter or path then when Lightroom imported the photo. If you restore the drive or media to its original state, the question marks will go away.