Issues with play back of MP4s after transferring files on SD card

[Android Central Question]

I bought a Samsung Tab 4 recently, I made the move from IOs to android and want to move media files that have had the DRM removed. I've converted the film's to MP4 and managed to get some onto the SD card and can be read. However, other files aren't being recognised when transferred across. I've tried with my S9 plus and put into the internal memory on both devices but the files aren't recognised. I've used different media players and checked that the files play on the PC before transferring to the SD card. But had no luck, has anyone got any advice?

 

[B. Diddy]

Welcome to Android Central! How are you transferring the mp4 files to the SD card? Are you inserting the card directly into your PC and copying the files over using Windows Explorer? Are you keeping the card in the tablet and connecting via USB to your PC to transfer the files?

 

[Rukbat]

I'm guessing that removing DRM (which is piracy) damaged the files in some way.

 

[B. Diddy]

Ah, good point. I thought the OP meant that the DRM was officially removed by the site where they were obtained.