when trying to play movie message"This file is protected"

When i try to play a movie form dirve the screen says "this file is protected. Protected files may play in safari it your device is authorized to view this content. Tap here to attempt to play this file in safari.

Will not work. why?

how can i fix it?

http://forums.sandisk.com/t5/SanDisk-Connect-Wireless-Media/IOS-8-Problems/m-p/333071/highlight/true#M431