Nobody can help you without exact info about comp settings, render settings, what's used in the comp and so on...
Sorry. My composition settings are these: http://gyazo.com/84dd6dfa7a6a618d49d1644cf0c55771
My render settings are these: http://gyazo.com/13a7514099f0dc7b0348e57bd1972cda
The composition is a promotional edit for a Call of Duty clan that I work with. My friend is the owner of it, and i wanted to help him out. I use simple effects like Optics Compensation, Radial Blur, all of these are defaults and they work fine. I also use ReelSmart Motion Blur and Magic Bullet Looks, but that's the problem. I managed to fix the first issue where it wasn't starting the render at all, but it got to about 30-40% or so and then it gave me an error about "Looks" and "RSMB". I didn't manage to screenshot it but after those 2 menus popped up and I said 'ok' to them both, this came up:
Any ideas as to what is happening?
I bet the source footage was recorded in some off-the-wall video codec that doesn't play nicely with AE. Transcode it to something AE likes and I think life will get better for you.
And don't use AE to render out that mp4. Use Adobe Media Encoder to do it.