Routing drives me nuts sometimes. I ask a Sim to go from A to B, and they take on a trip around the outside garden of the house only to stop somewhere near the sidewalk with the "impossible to get there" moodlet.
It also looks ridiculous when the path from A to B is clear, yet they stand still in front of an entrance as if it was clogged up.
It's hard to resist to the urge of just teleporting them and be done with that.