The event args for the RadDocking.ActivePaneChanged are named "ActivePangeChangedEventArgs" which I'm assuming is a typo for "ActivePaneChangedEventArgs".
Hello Rob, Thank you for sharing this with us. We are aware of the issue but changing this currently will lead to a breaking change in the control. However, we'll approve this report and think what we can do about it in the future. Regards, Martin Ivanov Technical Support Engineer