Server Error in '/' Application.

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[HttpException (0x80004005): The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).]
   System.Web.UI.ControlCollection.Add(Control child) +11659892
   Telerik.Web.SkinRegistrar.RegisterCssReference(Page _page, Control _control, String _url) +710

[HttpException (0x80004005): Please, see whether wrapping the code block, generating the exception, within RadCodeBlock resolves the error.]
   Telerik.Web.SkinRegistrar.RegisterCssReference(Page _page, Control _control, String _url) +815
   Telerik.Web.SkinRegistrar.RegisterCssReferences(ISkinnableControl _control) +1241
   Telerik.Web.UI.RadTreeView.OnPreRender(EventArgs e) +84
   System.Web.UI.Control.PreRenderRecursiveInternal() +132
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Control.PreRenderRecursiveInternal() +227
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3671


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4494.0