Some of my mkv files in my usb won't open or play

Hello

Please help me some of the mkv files or video in my usb wont play and it appears as a white paper thing and not a video file but some of the mkv files appears as a video file and it plays. I got those files from my friend's laptop and it shows as a video file and it plays. I want to transfer those files to my phone too but I can't since it won't play on my phone. My usb is 32gb. Thank you