Closed Unassigned: does not contain a script with hash code "3cf12cf1'". [27456]

We are seeing quite a few of these Application errors on our sites.
AjaxControlToolkit

Assembly "AjaxControlToolkit, Version=4.1.7.123, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e" does not contain a script with hash code "3cf12cf1'".

DeserializeScriptEntries

at AjaxControlToolkit.ToolkitScriptManager.DeserializeScriptEntries(String serializedScriptEntries, Boolean loaded)
at AjaxControlToolkit.ToolkitScriptManager.OutputCombinedScriptFile(HttpContext context)
at AjaxControlToolkit.ToolkitScriptManager.OnInit(EventArgs e)
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)
Comments: It seems that this error is caused by ToolkitScriptManager. Starting with the v15.1 release, we have removed it. So now, this problem is resolved.