Loose gas cap is a common cause of Check engine. Subarus really don't like loose gas caps, and it may take 120 miles to reset.
Looks like your whole Eyesight system has shut down because of the Check engine warning, too.
Get thee to the dealer!
This just happened to me today. Went to the grocery store, everything was fine. When I went to leave the store, the car started kind of funny and then all the lights came on. The car drives completely fine, but all systems (eye sight, etc.) are off. I have no time to go to the dealer this week, but will call tomorrow. So very frustrating.