1. Go back to the Slide Master tab and click Preserve Master. You can see a Pin icon appear on the left of the slide master. Then even if the selected slide master is unused, it can still remain in the presentation.
1. Go back to the Slide Master tab and click Preserve Master. You can see a Pin icon appear on the left of the slide master. Then even if the selected slide master is unused, it can still remain in the presentation.