This is the third post regarding this issue. There is another possibility to cause this problem. This is fatal and this is the root cause of my problem too.
It is glad that I found another post here http://xavierdilipkumar.com/post/2013/12/04/The-required-anti-forgery-form-field-__RequestVerificationToken-is-not-present-Ensure-that-cookies-are-enabled-in-your-browser.aspx.
The cause of the error message for me is really the Download Accelerator Plus (DAP). I have to uninstall it to get rid of the error.