There are times when a dialog may seem to not open. The dialog is most likely behind the CAD window. If a command has been issued and the dialog is not displayed, check the Task Bar for its icon. You can also hold down the <Alt> key and press the <Tab> key to cycle through all open windows. This will include non-PlantWise windows. You can also minimize the CAD window, find the dialog and then drag it to an area of your desktop where the CAD window will not cover it.