Video in files app not opening

I downloaded a 1GB movie from mediafire and it went into my files app but when i click on it the video doesnt load it only says "mpeg-4 movie" but another movie with the same size that i downloaded from the same place works just fine? And the movie that wont open worked the first time i downloaded but i accidentally removed it and now i cant get it to work again. Is there any solution to that?