Restart the game, it usually works for me. I have experienced this glitch, too. Try to exit Skyrim, then play it again.
That fixed it. Thanks!
I try to avoid using the console for anything, but I have had to a few times:
1. Most recently I used it to complete the Companions' Rescue Mission quest. I went to Broken Fang Cave and killed the vampires (very tough at level 22). Heimskr was not in the cage or the cave. I continued playing until now (level 63) hoping to find him wandering around somewhere. The quest marker showed him near the big giant/mammoth camp outside Whiterun, but no go.
2. I had to turn on God Mode at the end of The Break of Dawn because Meridia kept dropping me out of the sky to my death.
3. Turned on God Mode because the Spectral Dragon with the long-range carpet-bomb unresistable insta-kill (actually insta-multi-kill) breath weapon grounded behind the inn in Winterhold, where it enjoyed complete cover from arrows. Winterhold dragon fights are always challenging because the dragon will ground either behind the inn or atop the Archmage quarters, but this was definitely a Kobayashi Maru situation.