Undo previous action

View > Undo previous action reverts the state of Sirius to the previous state. The undo action applies to all components of the application.

To increase or decrease the number of save states, go to Viewers > Preferences > Other settings.Note that on slower systems enabled undo may cause some delays in executing commands, since each state needs to be saved before proceeding. If that happens, try turning undo off to make sure it's causing it. If so, keep it off except for more sensitive work where undo function is necessary.