Magnavox 4k blu ray player says No BMDV Exists in AVCHD Folder

[CM12884]

I just purchased a Magnavox 4k blu ray player today. The model number is MBP6700P. I have mp4 files on my USB flash drive that i tried to play on it but i get the message thats in the title. I would have thought that this would play mp4 files. Its one of the most common video files, not to mention the manual says it can play files on a USB device. It doesnt even mention anything about playing MKV or AVI files. I dont think ive ever heard of a player to not play any common type of video format. Im so confused. Is there any possible way i could get the files to play? If i have to convert them, which file would i have to convert them to? I have no clue at all lol. Any help on this would be greatly appreciated.