Asynchronous method debugging in VS 2013

Question

MS says I can debug the asynchronous method in VS 2013 http://blogs.msdn.com/b/visualstudioalm/archive/2013/07/02/debugging-asynchronous-code-in-visual-studio-2013-tasks- window.aspx

but when I try to debug the async method, it cannot display the local variable, everything is displayed as CS $ 0 $ 0001. I enter the variable name in the Immediate Window and says that the variable does not exist.

If I transform my function synchronously, I can debug as usual.

edit: This is not decompiled code. my WebView inherits from CefSharp.ChroniumWebBrowser