From the blog "Papyrus Stack Dumps "

There seems to be a lot of inaccurate information going around about what a "Stack Dump" is, what it means and what can be done to avoid them. Short explanation:   A stack dump is what is written to the Papyrus log file whenever the "stack" used by the game to track all the actively running scripts is full and no additional scripts can be run.   It is an occurrence that means your game didn't do something or multiple somethings it should have done at the time they were expec