Undo and Redo
The Undo and Redo features are an important element of editing PDF documents in PDF-XChange Editor. They can be used to reverse the most recent editing operation, or to redo operations that have been undone. These features are available in the upper-left section of the user interface:
Figure 1. PDF-XChange Editor User Interface, Undo and Redo Highlighted
Click the arrows to undo/redo operations as required.