Steps to reproduce:

• Create a general empty project
• Add Rectangle component to 2D View
• Open binding editor by clicking action icon beside "fill color" property in Properties view and selecting "Set Binding"
• In Binding Editor, open first combobox
• -> There are two empty items in the menu (probably these should be "Constants" and "button") See attached pictures.
• -> Selecting an empty item will crash Design Studio
• Open Connections -> Bindings and add binding for rectangle1
• -> "From" combobox has even more these empty items. Clicking those does not cause any crash though. See picture.