Missing Panels in Ci Tools Door or Window

Issue Description

Panels are missing in a window created using the CI Tools Door and Window tool.

Steps to reproduce

In a window, select a panel, apply a fixed pane then set a custom window sash but mis type or enter a value like "0" into the field. 

Then change the panel type to another setting.

DEF- XXXX

Workflow Error. 

Workaround

Clear the custom value from the Custom Window Sash field.

See video below for full steps