SYSTEM ERROR

SYSTEM ERROR
Message : An item with the same key has already been added. 
Source : mscorlib 
Trace : at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) at AjaxControlToolkit.ToolkitScriptManagerHelper.GetAssembly(String name) at AjaxControlToolkit.ToolkitScriptManagerCombiner.IsScriptCombinable(ScriptEntry scriptEntry, Boolean enableCdn) at AjaxControlToolkit.ToolkitScriptManagerCombiner.WriteScripts(List`1 scriptEntries, TextWriter outputWriter, Boolean enableCdn) at AjaxControlToolkit.ToolkitScriptManagerCombiner.GetCombinedRegisteredScriptContent(Boolean enableCdn) at AjaxControlToolkit.ToolkitScriptManagerCombiner.GetCombinedScriptContentHash(HttpContextBase context, String[] bundles, Boolean enableCdn) at AjaxControlToolkit.ToolkitScriptManager.LoadScriptReferences(HttpContextBase context, String[] bundles, Boolean forCombineAndMinify) at AjaxControlToolkit.ToolkitScriptManager.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)