Construction Plus causes an empty Ruby Console window to open when Sketchup 2018 Pro is opened. Also, (may not be related) when constructing a refrigerator cabinet only part of the cabinet is appears when constructed.
I’ll fix the Construction Plus Ruby Console problem in the next release. It causes no harm other than it is annoying. Could you please send me your .skp file that you are attempting to construct a refrigerator and fails. If it is larger than 10MB you may have to ZIP it. Send it to firstname.lastname@example.org.