I found a hearthling running continuously inside a window opening and got an error that I think is from that, but I’m not sure. 
The hearthling was able to reach the ground through scaffolding as far as I could tell, but he just stayed running in the window until knocked out of it by the placement of the top of the wall at the window.
I think I caught the error in the below saved game.
1512448515965.7z (2.6 MB)
And here are the errors:
release-765 (x64)[M]
CHECK failed: C:\rb\ihome\root\SH-OB0-BUILD\stonehearth\source\lib\lua\ai\execution_unit.cpp:205 bad unit transition “set_think_output” from “ready” in action pickup item type
stack traceback:
[C]: ?
[C]: in function ‘set_think_output’
…ehearth/ai/actions/find_path_to_reachable_entity.lua:61: in function ‘cb’
stonehearth/components/pathfinder/astar_search.lua:132: in function ‘_on_solved’
stonehearth/components/pathfinder/astar_search.lua:100: in function <stonehearth/components/pathfinder/astar_search.lua:99>
release-765 (x64)[M]
c++ exception: lua runtime error
stack traceback: