- in the layout view in wireframe mode, press the HOME key to make the entire board visible.
- click the green dot button of the selection toolbar to make all objects on the board selectable.
- with the mouse, select the entire board and all of the objects in it
- right click on the selection and choose PROPERTIES from the popup menu
- select the NETS tab of the dialog that appears
- place a checkmark in the DO NOT OPTIMIZE checkbox (this will turn off the minimum spanning processing of rats nest lines by PCB123 following changes to the board)
- press OK