I'm trying to use RadPrompt (and RadAlert/RadConfirmation) in a WPF app using Prism. I have followed this guide: https://www.telerik.com/support/code-library/integrating-raddialogs-(confirm-alert-prompt)-with-prism's-interactionrequest-using-mvvm . At the point I raise the interaction request, I can see that the RadWindow.Prompt gets called (and it's Owner is set to the calling Window), but no prompt window shows. I can't interact with the owner window so that suggests the prompt does exist, it just doesn't appear to have any visual element. What might I be missing here?