You are opening the render engine. Check the apps full name before you open. If you click After Effects and the render engine is still opening then you have a fouled up text file that is telling your system to only open the render engine. Please check to make sure you are opening the right application. If you are, please search this forum or Google for the simple text edit solution.
OMG i feel so stupid hahaha!
Daniel, I have a quick question: when you were having this problem, how did you open After Effects? Literally: what did you click or type to cause After Effects Render Engine to start?
Also, what operating system and version (ex., Mac OS X 10.10 Yosemite, or Windows 8.1) are you using?
We have recently seen an increase in the number of people who ask this question. There are multiple ways you can start After Effects, so I want to understand how you got from point A to point B.