Appears to happen when a Depot is full or trying to place colonists in the wrong plae.
(E.G. missing the depot and clicking the ground next to it or clicking something other then a depot by mistake.)

The mod Colony Builder (0.2.5) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event ColonyBuilder::on_player_reverse_selected_area (ID 192)
LuaCommandable API call when LuaCommandable was invalid.
stack traceback:
[C]: in function 'set_command'
ColonyBuilder/script_libs/script-units.lua:178: in function 'create_npc_group'
ColonyBuilder/script_libs/script-units.lua:331: in function 'colony_select_tool'
ColonyBuilder/control.lua:122: in function <ColonyBuilder/control.lua:119>

The mod Colony Builder (0.2.5) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event ColonyBuilder::on_player_reverse_selected_area (ID 193)
LuaCommandable API call when LuaCommandable was invalid.
stack traceback:
    [C]: in function '__index'
    __ColonyBuilder__/script_libs/script-units.lua:343: in function 'colony_select_tool'
    __ColonyBuilder__/control.lua:122: in function <__ColonyBuilder__/control.lua:119>