Sys.ArgumentTypeException: an object of type "Sys._Application" cannot be converted to type "Sys._Application". Parameter Name: instance

Question

I get an error message; Microsoft JScript MVC Error: Sys.ArgumentTypeException: An object of type "Sys._Application" cannot be converted to type "Sys._Application". Parameter Name: Instance

I am getting this error in my MVC application and I am wondering if I need to do this with upgrading to ie8? I have no problem in FF. The debugger finds an error in the MicrosoftAjax.debug.js file when I make a message.

Because I work in MVC, the usual solution; set ScriptMode to Release does not apply.

Answer 1

This may be what you were looking for. I spent all that day trying to find a solution, and every other article I read suggested either installing ScriptMode for release in asp:ScriptManager , or turning off SmartNavigation . This article suggests changing the following line in web.config to false:

 <compilation debug="false"> 

It worked for me, and with luck, it works for you too.

Answer 2

I was getting an exception in ScriptResource.axd :

 Sys.ArgumentTypeException: Object of type 'Object' cannot be converted to type 'Array'. 

Changing ScriptMode to Release fixes the problem.