Edited Unassigned: ClientCssResource : css lot loaded [27988]

Hello,

We have a problem with ClientCssResource.
We upgraded a old version of ajaxcontroltoolkit : 3.5.7.123 to 15.1.4.
(see this issue : https://ajaxcontroltoolkit.codeplex.com/workitem/27986)

we are using ajax server control that inherit from other ajaxcontroltoolkit controls, like explained in this tutorial :
http://code.tutsplus.com/tutorials/asp-net-ajax-server-controls-with-client-side-functionality--net-26166

So we included CSS file like ressource embedded :

```
[assembly: WebResource("PluginControl.PluginTest.js", "application/x-javascript")]
[assembly: WebResource("PluginControl.PluginTest.css", "text/css")]
namespace PluginControl
{
[ClientScriptResource("PluginControl.PluginTest", "PluginControl.PluginTest")]
[ClientCssResource("PluginControl.PluginTest.PluginTest.css")]
public class PluginTest : ScriptControlBase
{}
}
```
But with new version the css is not loaded and no error or warning is display.
Can you help with this issue please ?

I join file with the problem, as you can see PluginTest.css is not loaded.

Thank in advance,