Well I took a look in the repository, and the video file I published appears to be intact 100% unmodified (same name from Adobe Stock, same format, same size, etc.). I am able to play the video in the default WIndows 10 video player.
Looking back through the manual, it states multiple prerequisites for the MagicPlayer I to function 100% with all media.
I went and downloaded Adobe Flash Player System Plug-In, Firefox, Adobe Reader and the K-Lite Codec Pack (all but MS Office as suggested by the manual).
Interestingly enough, upon rebooting the machine, it now plays the video fine! Unfortunately I can't tell you exactly which package did it (other than it was probably not the Adobe Reader
)
Hope this helps!