After Effects Export Problem

[o0BenMc0o]

Hi, when I try to export my video from after effects, the screen randomly goes a white/gray color over the image, I need help stopping this!

The render settings I'm using are: H.264, 1280x720p, 59.94fps.

Here is an example of the problem - http://gyazo.com/8a993bf99949fcf4db7ecb799a908fb6

Thanks,
- Ben.

 

[simsaladimbamba]

What are the project settings?
What codec does the source video use?
What effects/layers are applied? Have you tried rendering samples with different effects switched off?