If you use AJAX Control Toolkit in your project you probably use
You have tested your web application many times in your Dev environments and everything worked just fine. So what you've changed is you used a Web Deployment Project to build and deploy your web application and you presumably wanted to take advantage of a famous precompile and merge feature of the WDP.
Use standard ASP.NET
ToolkitScriptManagerand everything will work again.
I am in a process of investigating whether a
ToolkitScriptManagerbrings any advantages comparing to a new
ScriptManager3.5 in terms of more efficient HTML rendering and will post here my findings as soon as possible.
Also if you are interested in employing a ToolkitScriptManager together with the Web Deployment Project I invite you to vote for this bug on Codeplex.