Media player video texture is black in one project, and not black in others

Is this map created with Static lighting? If there are now movable or stationary lights in your scene then the engine will have not light data to map onto your actor and it will appear black as the game believes there are no light sources affecting it. Try bringing in a “movable” point light above the actor and build lighting. Report back if this is not the problem, if not it could be a matter of looking at you’re projects render settings.