Ok..... I updated my Nvidia Shield.  (I wouldn't have done it, but it does it automatically, if you don'y.)   The problem is. Emby and Emby server were both on a USB drive formatted as internal memory. Now, My movies are all there, I mean the artwork for them etc. BUT if I try to play anything, it can no longer access the drive. (I've checked every permission.  VLC can access it, but not Emby, I am ok, reinstalling the server, if I have to. There should have been a back up in the