... and for the record, I'm not using UF3P, and I don't seem to be getting the errors (except in excessively large cells with equally large navmeshes).
[Edit]
... and now a thought occurs to me. pkleiss, did you ever try getting the error, and then saving, exiting the game, and restarting it with the same mods loaded? Maybe a simple reload pops the NPCs in the head...
I'll try that now... testing...done
You were right PoHa, just the mere fact of saving, exiting and resarting the game made the NPCs work right - all without UFO3P used. But that still doesn't explain why with it, I can't get the error to occur.
Hmmm. I think I'll try to get the error again with UFO3P installed -> better testing = better solutions right?
Well, F*** Me - I got the error using UFO3P. Son of a ...
So now I'm in the same boat as everyone else. Man I must have tried that 10 times in the past, but this time it occured. Guess I'll remove my post about UFO3P then and make my GD mod an esm.
BTW- the cell I use is large with lots of navmesh triangles. I guess the question now is how many triangles is too many.
EDIT: OK so I took my original cell with its 1445 navmesh triangle and optimized it -> 1197 triangle, tested, got the error.
Then I began removing navmesh triangles: 940 -> error, 487-> error, 280 -> error.
I'm not willing to test below 280 triangles because it isn't worth it to have that as a limitation on navmesh triangles. In the end I didn't even need to use fast travel to get the bug. Just leaving my custom cell area for the vanilla area and returning caused the error.
So the current solutions (if you can call them that) are to either save, exit, reload an esp or make your mod an esm.
PoHa - How few triangles do you have that you don't get this error. Have you tried leaving a custom cell for any vanilla area and returning? I am trying to help out but its seems that I just keep getting different manifestations than everyone else. I can't believe I couldn't reproduce this before cause now I can reproduce it in the simplest of ways. Everytime tonight (and I have tested 12 different ways) all I have to do is go to a vanilla area, return, and the NPCs are fubar. Going to different cells within my mod doesn't seem to affect it though. :shrug: