When you add three-dimensional (3-D) effects to a placeholder on a slide master and then delete all of the 3-D effects from the placeholder in Normal view, the 3-D effects return to the placeholder.
Note: Common placeholders include shapes or title placeholders.
Do either of the following:
Delete only some of the 3-D effects from the placeholder, or remove all of the 3-D effects from the placeholder in Slide Master view, to make the placeholder two-dimensional (2-D).
In the Format Shape dialog box, click the 3-D Rotation pane, and then under Text, select the Keep text flat check box.
To show the Format Shape dialog box, right-click the shape or object, and then click Format Shape on the shortcut menu.