Scripts silently fail when moving NPCs between cells.
I've noticed a few times that NPCs don't appear in locations where they should move: Mehra Milo didn't go to Holamayan during the main quest; Varvur Sarethi didn't come to his room after rescuing him from Venim's. There were no errors in log. For some reason, when I reloaded and tried those quests again, everything was OK. But now I'm playing Tribunal, and this issue showed up again in "Helseth's Champion" quest. When you take this quest, Karrod goes to "The Winged Guar" and after 24h he should return to the throne room - but he stays in the bar, and if you come to Helseth to start the fight, you end up locked in the room without an opponent. The script itself seems to run correctly, but the actual moving command Karrod->PositionCell 111.062 -76.603 -68.484 0 "Mournhold, Royal Palace Throne Room" just doesn't do anything. No errors and no movement. Running it from console in the throne room had the same result. Then I went to The Winged Guar where I found Karrod, and run the command again - it worked. I return to the throne room, see Karrod there, speak to Helseth, guard clear the arena, but Karrod refuses to start the fight. I tried karrod->StartCombat Player - it did not work, but clicking on Karrod and running startcombat player made him to start. Strange thing is that while we were in "The Winged Guar" before forcing his return, karrod->StartCombat Player command was working.