Note 4 edge with tmobile is having a micro sd card issue

[AC Question]

Sometimes when I watching a movie on the note 4 edge that has been stored on the micro sd the movie will stop and then the phone says that an sd card is not installed. I close the video app and re-open it and the movies reappear and i am able to open the movie I was watching but it is from the beginning, not from where the movie stopped