Ive been trying to solve this for about 2 hours, its so frustrating, its such a simple problem, i will put my system specs below just in case.
Mobo: Gigabyte MA770-UD3
GPU: Powercolour Radeon R7 250X
Processor: Amd Phenom Quad Core Black Edition clocked at 2.7GHZ
RAM: 4GB DDR2
Monitors: 1x Acer V193 1x Liyama ProLIte E2483HS
HDD: 1TB WD Blue
OS: Windows 7 Ultimate x64 2009
Nobody can tell you anything without exact render settings or details about the comp just as wel las version of AE and how you actualyl verify the output.
First, make sure that you are viewing the Active Camera in the Project Panel. You may be looking at another view. Only Active Camera will render.
Second, use one of the standard Output Module or Adobe Media Encoder presets to render your movie. If that does not solve the problem we need a detailed description of your workflow. I'm guessing that you are new to AE and that this is one of the first projects you have tried to render. If so please spend a half hour here: Basic Workflow. The last section is on rendering.