Sys.ArgumentTypeException: Object of type 'Sys._Application' cannot be converted to type 'Sys._Application'.Parameter name: instance

Question

I am getting the error; MVC Microsoft JScript runtime error: Sys.ArgumentTypeException: 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 it is to do with the upgrade to ie8? I do not get the problem in FF. The debugger locates the error in the MicrosoftAjax.debug.js file when I am doing a post.

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

Answer 1

This might be what you were looking for. I've spent this entire afternoon trying to find a solution and every other article I read suggested either setting ScriptMode to Release in the asp:ScriptManager or disabling SmartNavigation. This article suggests changing the following line in your web.config to false:

<compilation debug="false">

That worked for me, with any luck it will work for you too.