It might mean the badit is already dead. And hasn't respawn yet.
I have a permanent Misc Quest to kill the bandit leader at Rift Watchtower. Although I check it off correctly, highlighting it and trying to zoom to it produces nothing. I had killed everyone there just wandering through very early in my character's career (less than level 20), I am now level 60+ and they still haven't respawned, and I still can't get any arrows to point me there.
At least I am not the only one stuck with this. I haven't yet tried console commands to fix it (it's just not that important to me). I'm thinking forcing the cell to reset may work better than forcibly advancing the quest (if the forced reset even works).