Mission Control not working after system upgrade to macOS Sierra
I had a similar problem with a Mac Book Pro (late 2011). I did a clean installation of macOS Sierra and Mission Control and Launchpad were not working, but it did not restart the Dock when I tried to open any of them. I researched a bit I tried killall Dock on the Terminal, for restarting it manually and that worked for me.

Give it a try. Maybe doing it manually will make it work.