Difficult to describe after one observation. I selected an IC and all its connections to try and move it. All the connections got messed up like the nodes would not move together with the component. Trying to undo had no effect. The components would not let go of the mouse cursor when I tried to drop them at a new location. Tried Escape key, double-clicking. Nothing I know could make the app complete the Drag/Drop operation until the error message came up.