I HAVE LUMIA 630 DUAL SIM IN WHICH WHEN I PLAY A MOVIE AFTER SOME 10-15 MINUTES THE PLAYER SWITCH TO THE NEXT VIDEO AUTOMATICALLY WHAT COULD BE THE PROBLEM ? i'm using moli player.
if this to answer my question, i would say file size doesn't matter, but if the bit rate is high, the SD card might not be able to handle it.
on my surface 2, i have a 64 GB SD card - which i bought thinking it was fast.... at least that's what it said... but every time i watch a 1080p movie from the SD card it stops...i have to copy the file on my internal memory, the watch it.. this way it work perfect.
then i came to understand that SD cards have Classes which affect their transfer rate properties.
so i would say at least test my theory. even try using the the SD card on a different device.
of course all of this is an assumption that you are actually using an SD card