@box said:
Your preferences dialog is appearing off screen, have you recently changed your monitor layout?
Go Window/Preference to get the focus on the dialog, then hit alt and space together, then m, then tap any arrow key once and without clicking anything, move the mouse around until the preferences dialog appears on the screen.
While you have it there go to Workspace and hit the reset workspace button.
Holy mackerel...you are a life-saver! Yes, we had been adjusting monitor layouts recently.
Thank you so much!