In the very first loading screen with the petals, the progress bar goes about 2/3s of the way and then the game crashes with "Far Cry 4 has stopped working".
I had a pretty similar problem when I first installed it. I also verified the files a few times and it kept saying I had to re-download a couple GB of the game. I ended up uninstalling it altogether and then re-installing it and that seemed to fix it.