On production machine: AjaxControlToolkit requires ASP.NET Ajax 4.0 scripts.

I was helping my colleagues to debug one weird bug on ASP.NET 4.0 website. Everything worked well on developer’s machine, but after publishing to IIS 7.5 Windows 2008 R2 Webserver, we always got site partially working. Everything worked, except AJAX Control Toolkit controls. There were no any signs of errors. Ajax controls just were not …