Yeah thanks Todd. I kept my 2014 AE intact...but apparently missed that on the media encoder. This will get me back in business for now.
I'm thinking the issue I'm having with this file in 2015 is the continuous rasterization of an AI file that is being used as a 3D layer. I fly the camera through it, which means it is creating a monstrous pixel resolution on the fly. I remember this being a problem in an earlier 2014 version, but it eventually got addressed. Hoping this can be addressed quickly with 2015's new architecture as this is a workflow I use a lot. (Vector art from AI brought in and turned into 3D layers)
Sorry for dilluting your thread. I'll take this to the Adobe forum.