Engine Error - Undo during build

Summary: Engine error popups during construction - use of undo tool.

Expected Results: Undo of building

Actual Results: Undo continues but error re-occured (see engine error #3 for second instance)

Notes:

release-695 (x64)
std::logic_error: 'error while loading: no such object 687157’
stack traceback:
[C]: ?
[C]: in function ‘load_object’
…ehearth/services/server/build/build_undo_manager.lua:139: in function 'undo’
stonehearth/services/server/build/build_service.lua:127: in function <stonehearth/services/server/build/build_service.lua:126>

release-695 (x64)
c++ exception: lua runtime error
stack traceback:

release-695 (x64)
std::logic_error: 'error while loading: no such object 686523’
stack traceback:
[C]: ?
[C]: in function ‘load_object’
…ehearth/services/server/build/build_undo_manager.lua:139: in function 'undo’
stonehearth/services/server/build/build_service.lua:127: in function <stonehearth/services/server/build/build_service.lua:126>

Version Number and Mods in use: No mods, Steam Unstable release-695 x64