Here is a bug I have seen very rarely, but from the beginning, and now with the latest patch too:

I am walking completely alone (without companion) and suddenly the dialog/interaction system activates and offers interaction with a NPC which is obviously far away, but in the same (or a loaded nearby) cell.

The first time I remember was a long time ago, I was walking around near Bunker Hill, and suddenly interaction (talk to) with a NPC named 'Scavenger' was shown. But there was no NPC near me! I tried to 'talk' to him, but nothing happened. It was not repeatable endless, and as soon as I moved I could not find it anymore. And I did not see any NPC near me. Later as I walked near the Constitution (I did not do the quest yet and was not in this place, saw it only from a distance) I saw several 'Scavenger ' NPCs, they were peaceful and too far to interact - I suppose these were the NPCs for the Constitution quest. I suspect I 'interacted' with one of them, but from a very far distance.

The second time this happened was yesterday, I was on a quest walking around (actually coming back from) the Dunwich Borers. I was in sneak mode, and suddenly I had a red pickpocket menu on the screen. It said 'Gunner' and as I used it, I could try to steal an item from the Gunner NPC. But there was no NPC near me at all!

There are no gunners near Dunwich Borers! They are all at Hub City Auto Wreckers! Since I have no pickpocket perk, I failed, It said I was caught, and then the sneak mode changed to red and 'Danger'. There was an explosion very far away at Hub City Auto Wreckers as if they had lobbed a grenade at me or even a mini nuke, but nowhere where I really was!

There was nobody near me, and I did not take damage, and the sneak mode went back to green very fast. So the NPC AI did somehow 'see' me, but only for a very short time and obviously in a very wrong place.

Regrettably both situations are not repeatable. I can offer no save to check. And it happens very rarely. It is also not very critical, at least not in the form it happened to me. In both cases it was soon clear, that nothing was near me, and I could do nothing. I think if I had succeeded pick pocketing the item it would have failed every time. The pickpocket was only because I was sneaking, otherwise I could have tried to talk, or not, since this was an enemy.

But I still want to report it, since it could make other problems more critical and it is clearly a bug.

Playing on PC, Windows 7, GTX 980Ti, 16 GB, Core i7 4820 - no problems, no crashes. Not using any mods, not using console.

Edit: Typos, clarity.