PinballFX will crash if you or any of your friends that play PinballFX have a broken large(186px) avatar.
I changed mine and defriended everyone else who was a culprit including Matt Thrower, Dogmatix, Duke of Chutney and Stonecutter. Just go to your profile and upload a large avatar and then refriend me. It's something to do with leaderboards and being unable to deal with a broken avatar in Steam.
Crash to desktop. 'Pinballfx is not working'. If you are crashing on the table selection menu...this is it.
Find all of your friends who play pinballfx check their individual profiles (you won't be able to see large avatars on the summary). If they have a broken large avatar, message, then defriend them. Check your own profile as well. Upload a new avatar if necessary. It will cure the menu crash.