One of my family members that I share my library with contacted me to say that two movies they tried to watch had no video (black screen) and only had audio. I have tried the same movies and they work just fine on my Apple TV, Windows computer, and Roku. PlexPy says that their device is a Samsung TV UN46H5203, if that helps. The movies have been prepared like all of the others in my collection and are M4V encoded. Other movies in the collection do not have that issue (that they have noticed so far).
Any thoughts?