GoToPage() method is not working correctly in some cases when called in DocumentChanged event handler. The known cases are described below: 1. When RadPdfViewer and the document are loaded initially and document is set through the RadPdfViewer.Document property. Workaround: DocumentSource property could be set (in XAML or in code-behind) instead of the Document property. If the Document property is used, this should be done after RadPdfViewer is loaded. 2. When the ScaleMode is changed in DocumentChanged event handler and then GoToPage() method is called in the same event handler.