Server Error in '/' Application.

Could not load control AjaxControlToolkit.ComboBox. The script reference(s) of this control was not loaded correctly. If AjaxControlToolkit.config is used, probably this control is not registered properly.

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.Exception: Could not load control AjaxControlToolkit.ComboBox. The script reference(s) of this control was not loaded correctly. If AjaxControlToolkit.config is used, probably this control is not registered properly.

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:


[Exception: Could not load control AjaxControlToolkit.ComboBox. The script reference(s) of this control was not loaded correctly. If AjaxControlToolkit.config is used, probably this control is not registered properly.]
   AjaxControlToolkit.ToolkitScriptManager.OnPreRender(EventArgs e) +387
   System.Web.UI.Control.PreRenderRecursiveInternal() +90
   System.Web.UI.Control.PreRenderRecursiveInternal() +163
   System.Web.UI.Control.PreRenderRecursiveInternal() +163
   System.Web.UI.Control.PreRenderRecursiveInternal() +163
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +906


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.3928.0