Lightroom Import will only show previews for a few of the files in the Camera Roll on my phone, then when I try to Import, it quits part way through,. When I cancel the Import, the Import button is then greyed out, and when I try to quit Lightroom to start over, I have to Force Quit. This problem has spanned a few Lightroom and iOS updates. I've switched cables and tried anything else I can find in other posts. I hope someone can help.