Media Players and their associated textures do not render in standalone game or in a packaged project.
Found on: //UE4/Release-4.11 CL-2897738
Checked 4.9.2 Binary from launcher, issue occurs there as well, not marking as a regression.
Result: In editor the movie player plays, but in standalone it renders as a default texture. If one was to package the project (File > Package > Win64) a similar result would occur, except instead of being default texture it will simply render black.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-28011 in the post.