Save to camera roll doesn’t work anymore

I updated and suddenly began having an issue. I normally scroll my dropbox files on the iPhone Dropbox app, saving specific photos to my camera roll, either by pressing on them until “save to camera roll” shows, or by exporting and saving to camera roll. Suddenly, since updating, both of these actions lead only to a light gray/white blank file in the camera roll- just a grayed our square with no image. I updated again, but it is still happening.. I can not find a workaround, I can find no way to save from the Dropbox app into my camera roll. Any help would be much appreciated ...