I am trying to use C# and Jquery to look and see if a file exists. If it does, then it will download it through a File command, but if it doesn't, then I want to post a message on the screen saying that the file was not found. Everything works, except when I run a cross a file that is not there, I get an error that says:

"This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet."

I tried to allow the get, but it gives me a blank page with the response text on it instead of allowing me to load it into a div tag for display on the page.

Any ideas why it would returning as a Get instead of a POST and how i can modify it to fix the error?

Here is my Jquery code:
Code:
function SoftwareDownload(FileName) {
    $('#DownloadResults').text("");
    $.ajax
    ({
        url: 'addr',
        type: 'POST',
        data: "fileName=" + FileName,
        dataType: 'json',
        success: function (response) {
            $('#DownloadResults').text(response);
        }
    }); 
}
and my C# code
Code:
public ActionResult SoftwareDownload(string fileName, DownloadModel model = null)
        {
            String downloadLocation = (Address is correct ... removing for posting resaons);
            try
            {
                FileStream fs = System.IO.File.OpenRead(downloadLocation + "\\" + fileName);
                return File(fs, "application/zip", fileName);
            }
            catch (Exception)
            {
                string response = "File Not Found";
                return Json(response);
            }
            
        }