This is a safety net as it enables you to take your design back to a stage beyond the number of histories you have set in the History Window.
If you find that you have made a mistake and would like to get back to a stage beyond what is achievable using the History Window, go to the File Menu and select Revert to Saved. This will take you back to the last saved version of the design.
Tip: Although you have the option to use Auto Save in AVA, this does not replace the act of saving the file, and we recommend you save your work regularly. Use the keyboard shortcut command S to do this.