Toolkit not working

I started a new website and added AjaxControlToolkit.dll to my bin folder.  I also installed it in Visual Studio (and it works in other websites).  I am getting the error below but do not know how to get it to work. Thanks.

Message: Could not load file or assembly 'AjaxMin, Version=4.97.4951.28478, Culture=neutral, PublicKeyToken=21ef50ce11b5d80f' or one of its dependencies. The system cannot find the file specified.

 Stack Trace:
   at AjaxControlToolkit.ToolkitScriptManagerCombiner.OutputCombinedScriptFile(HttpContextBase context)
   at AjaxControlToolkit.ToolkitScriptManager.OnInit(EventArgs e) in f:\TeamCity\buildAgent\work\80acd78aa4c25314\Server\AjaxControlToolkit\ToolkitScriptManager\ToolkitScriptManager.cs:line 192
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)