Undoing & redoing

To undo or redo an action, simply click on it's row in the panel list. The document will revert to the state when the chosen action was performed. No changes will be lost until you change anything in the document, while having the previous state chosen. If you make changes to the document while not being on the bottom of the list (last action performed), all the further changes will be lost. The only way to get to the lost state is to have saved it as a Version before.