Having started a (new) game, explored for a bit and gotten to the place where my last hideout was with a truck, I encountered a bunch of NPCs along the way. Then one of them started giving me creepy and rather annoying ERRORS ™.

Usually, I just skip error messages like this. But every time I turn my truck so that the NPC is out of my sight, the error turns into an ‘empty path’ one instead and every time the NPC is in my view, the friendly “We can see u” error message comes up.
If it helps to locate the bug, the only thing I think may have caused the errors is that I have kept ignoring the requests of the error-giving NPC to “talk”. The NPC herself is located directly in the middle of a river so it is not possible to talk with the NPC to look whether the error goes away (by doing this) or not.
PS: The error message has, so far, came up every turn for me.
PSS: This bug occurs in the latest version of Cata. (Jan 13)