Smoke not appearing when rendering animation It's my first time using blender. I am making relatively simple model of an object that emits two "smokes" with changing color- one from the top and one from the bottom of the object. Therefore, I have two smoke domains at the top and the bottom. The smoke on the top has to go up and the smoke on the bottom has to go down. The smoke on the top has density different from 0 in the first half of the simulation and then its 0 for the second half so that its not visible. The opposite happens for the smoke at the bottom. When I look at the animation in the openGL render active viewport, everything looks as it should be and I see "both smokes". However, when I render the animation I do not see the bottom smoke at all when it is supposed to be visible in the second half of the simulation, but I see the top smoke properly in the first half. Why is that? 

I need urgent help!!! Thank you in advance!

I am attaching the .blend file in the link:
https://www.dropbox.com/s/qwtdr0998susm9k/6ri.blend?dl=0

Best,
Nenko
You didn't checked Density on the Influence panel of the Voxel Data texture for you bottom domain.