Flixster downloads galaxy tab 3

A

AC Question

hi
hope someone can help
bought a tab 3 so that i can download my ultraviolet films to watch on the plane and at hotel.

installed the Flixster app from play store and it shows alll of the films that I own. Started downloading them on to my 64 gig sd card and all seemed fine. tab reports that they are downloaded and the mp4 file can be seen in "my files". When i look in flixster they either dont show up as downloaded or only one of them will??? I tried switching off the internet connection as flixster claims that it will automatically default to playing offline downloads without one but still no joy. i have also tried closing flixster and then opening it again.
Am I doing something wrong?
Please help a lady in distress :)