Can not render After Effects CC project as mp4 / h.264 any more?
All Adobe video products are intended to target consumer formats through Adobe Media Encoder since CC 2014, After Effects has almost only intermediate formats now in its internal renderer (which is essentially the exact same thing as the one in AME).

Instead of clicking on "Add to Render Queue" you click on "Add to Media Encoder Queue" and in AME you will have all the formats you had before and even a few more.

This has the advantage that you can continue working on your project while AME is rendering your composition. No need anymore for a background render plugin.