I have always shared video from my windows 10 pc to my imac (el capitan) wirelessly without issue. No all of the sudden any new movies that I put in my movies folder, it says that I need to contact an admin. I am the admin on both computers. The MAc sharing has me, my pc accoutn and everyone with read/write access yet any new videos will not open. What could be causing this and how can I ensure all sharing is correct?