Will this plugin work for Sketchup Make (v13)

When I run it I see this error in the ruby console with a simple two cube grouped system.

Error: #<TypeError: wrong argument type (expected Sketchup::Entity or Array of Sketchup::Entity)>
(eval):127:in add' (eval):127:in set_current_point'
(eval):73:in `onLButtonUp'
(eval):127