I have a problem with the new Mocha not taking my MP4 files. Also After Effects doesn't render for tracking inside. I am on free trial, Because I just got a new computer. I Do plan on getting it when the trial expires, and I have used it for a long time and have experience working in mocha. I have the newest version of the After Effects Creative cloud.
Use CC 2014, not 2015.
For use in mocha, I recommend tiff or jpg image sequences. ProRes quicktimes are also a good option.