When EventBinding is used in XAML to bind commands to events of Window or RadRibbonWindow (as it inherits Window), InvalidOperationException is thrown in design-time. Workarounds: 1. Attach an event handler directly to the events of the Window (RadRibbonWindow) 2. (more MVVM-friendly) use Behavior to attach the appropriate event handler.
Hi, The fix for the issue will be available in next LIB version (2018.2.611). It will also be included in our next official version – R2 2018 SP1, scheduled for the end of June. Best regards, Ralitsa Kumanova