I am trying to send image using ajax post to asp.net web form
function SubmitFunction() {            
            alert(imgData_Based64String);
            imgData_Based64String = "test";
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "WebForm1.aspx/SaveImage",
                data: "{ 'Based64BinaryString' :'" + imgData_Based64String + "'}",
                dataType: "json",
                success: function (data) {
                },
                error: function (result) {
                    alert("Error");
                }
            });
        }
    [System.Web.Services.WebMethod]
    public static void SaveImage(string Based64BinaryString)
    {
        string Value = Based64BinaryString;
    }
Everything is ok.
"test" message arrived to server side SaveImage function.
But when I tried to send actual based64string (After removing "test" dummy message) 
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAoAAAAHgCAYAAAA10 ....
It never reach to server side SaveImage function. It only show below error at Browser developer mode.
Failed to load resource: the server responded with a status of 500 (Internal Server Error) 
 
     
    