Telerik Control Stylesheet Is Not Registered after an AJAX Request

Environment

Product

Progress® Telerik® UI for ASP.NET AJAX

Description

When working with Telerik UI for ASP.NET AJAX and the control is not initially visible on the page, the Telerik control stylesheet is not registered after an AJAX request (inside MS UpdatePanel).

Solution

If the control is initially invisible and is shown after an ASP.NET AJAX update, manually register all the required CSS files in the head tag of your page as shown below. Otherwise the control will not be displayed correctly.

<link href="<my_path_to_stylesheet>" rel="stylesheet" runat="server" >

Alternatively, replace the MS UpdatePanel with RadAjaxPanel or ajaxify the control with the RadAjaxManager. Thus, the stylesheet will be applied properly after an AJAX request even if the Telerik control is initially invisible.