If you run out of energy, you cannot go into a new mission. Don’t worry though, you can find more energy in the Supply Crates around your map.
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
The Walking Dead: Our World
I’m out of energy and can’t go on a mission! – The Walking Dead: Our World
- by game guide