If you change your mind about an edit or effect, Adobe Premiere Elements provides several ways to undo your work. You can undo only those actions that alter video content; for example, you can undo an edit, but you cannot undo scrolling a panel.
To undo changes made before you last
saved a project, try opening a previous version in the Premiere
Auto‑Save folder. Then choose File > Save As to store
the project outside of the Premiere Auto‑Save folder. The number
of changes you can undo depends on the Auto Save preference settings.