Endless Loading screen is shown over RadPane when the set_showContentDuringLoad(false) method before changing the contentUrl of a RadPane (which is already showing another external page).
Workaround: Set the ShowContentDuringLoad="false" property of the RadPane in the markup initially
Code to reproduce the bug:
<script>
function loadNewPage() {
var contentPane = $find("RadPane2");
contentPane.set_showContentDuringLoad(false);
contentPane.set_contentUrl("newContentPage.aspx");
}
</script>
<telerik:RadSplitter ID="RadSplitter1" runat="server" Width="100%" Orientation="Horizontal" Height="800px">
<telerik:RadPane ID="RadPanel1" runat="server" Height="30px">
<asp:Button Font-Italic="true" runat="server" Text="Load New Page" OnClientClick="loadNewPage(); return false;" />
</telerik:RadPane>
<telerik:RadPane ID="RadPane2" runat="server" ContentUrl="https://www.wikipedia.com">
</telerik:RadPane>
</telerik:RadSplitter>