Error: Reference to tree table entry that does not exist.
This tells you that something is trying to interact with an object in some invalid way (usually a personglobal type interaction with a non-person).
Stack Object name: N001_User00580 - Grace
Node: 26
Tree: id 4187 name 'Start Visiting - Pet - Find Something To DO' version -32754
from Controller_Visitor
Prim state: 0
Params: Locals: 13 159 1 2 1
The problem node is this one (from Controller_Visitor):
1A: Push Interaction: getting interaction # from Local 4 of Local 1 onto the stack object's queue, autonomous priority, Icon Index is 0x1, use name; true: 20, false: 0
This is basically a Sit in some chair interaction, but a special version that was designed to work with pets, and the problem is that the game can't find this interaction in the chair. I'm assuming there's a custom chair or chair hack of some kind.
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