Changes to the selected skeleton can be undone with the Undo button at the top of the plugin interface. Undone changes can be redone with the Redo button. Expand the History list to see the list of changes that can be undone.

Use the small buttons to the right of the main button to undo (or redo) all the changes in the history list at once.

Motion Studio undo is separate from trueSpace undo. If you are working with any object related to a Motion Studio skeleton, you usually want to use Motion Studio's Undo. Don't worry about using the wrong Undo, because trueSpace and Motion Studio both have Redo buttons. Also, if you accidentally use trueSpace undo instead of Motion Studio undo, Motion Studio can usually still undo the change correctly.

The Restore button restores the keyed pose for all skeletons at the current frame.

The History panel can be expanded to display a list of all actions in the current undo list.