I'm trying to render an animation I made using blender models and textures, but all I get is a grey screen on the Rendered viewport and output.
On the left there's a Rendered Camera view, and on the right my objects in the Solid Viewport

I tried doing some researching to see what I was doing wrong, but unfortunately I couldn't find anything. Here's what I've tried:
- See if something is up with lighting and camera, and apparently it's not;
- Disabling "Sequencer" from Render > Post Processing;
- Switch from Blender Render to Cycles Render, but it didn't worked either and the output it's the same;
- Copy one of the objects from the original scene and place it on a new Blender file, containing just the starting cube. When I rendered through Blender Render, I could only see the cube. However, when rendering through Cycles, it rendered both objects with their following materials.
Here's the experiment on a new Blender file, and the Rendered view shows both objects

Do you guys have any suggestions of what my problem might be?
EDIT: addded .blend file below.

