Free Standing Wall Engine Error

While building a free standing wall I some how ended up with a single block open between the last column and a cliff edge when I went to close this hole I got this error message-

release-687 (x64)
…th/services/client/build_editor/wall_loop_editor.lua:293: attempt to index local ‘blueprint’ (a nil value)
stack traceback:
[C]: ?
…th/services/client/build_editor/wall_loop_editor.lua:293: in function ‘_can_contain_entity’
…th/services/client/build_editor/wall_loop_editor.lua:76: in function ‘_location_filter_fn’
…ces/client/selection/entity_or_location_selector.lua:214: in function ‘filter_fn’
…nehearth/services/client/selection/selector_util.lua:23: in function ‘get_selected_brick’
…ces/client/selection/entity_or_location_selector.lua:201: in function ‘_get_selected_brick’
…ces/client/selection/entity_or_location_selector.lua:267: in function ‘_on_mouse_event’
…nehearth/services/client/selection/selector_base.lua:115: in function '_mouse_cb’
stonehearth/services/client/input/input_capture.lua:55: in function '_dispatch’
stonehearth/services/client/input/input_service.lua:70: in function '_dispatch_input’
stonehearth/services/client/input/input_service.lua:12: in function <stonehearth/services/client/input/input_service.lua:11>
Steps to reproduce:
This was the second free standing wall I built in the course of this game instance. I had no such problem with the first wall.

Expected Results:
Add 1 column to fill space
Actual Results:
Blueprint fail

Screenshot of the single space that caused the error

Version Number and Mods in use:
A19 release 687 (x64)
rayyas children mod
System Information:
Windows 10 (x64)
Nvidia GeForce GT 730
24GB Ram
5TB Hard Drive Space