Sounds like a codec issue - present on one computer, not the other.
In the "bad" computer, Encore is activated, right?
Can you play one of the m2v files from the Encore library? Example, on my pc, C:\Program Files\Adobe\Adobe Encore CS6\Library\Entertainment\NTSC\NTSC_Nightlife.m2v
Yes, the same file you showed above is playing just fine here for me. And yes, Encore is activated.
Thanks, so far, for the answer.
What is the source of your m2v? Did you export it? I would look at the characteristics of that file.