Getting text/html Response instead of application/json on user machine in case of Exception-CodePudding

I am experiencing strange issue with JSON response.

MVC Application A hosted on Server A. when user browse the URL which internally calls MVC action for fetching data in UI using JQuery Ajax.

MVC action :

    Try
       Return Json(mRetResponse, JsonRequestBehavior.AllowGet)
    Catch ex As Exception
                    HttpContext.Response.StatusCode = System.Net.HttpStatusCode.InternalServerError
                    Dim mErrorMessage As String = ex.Message.Replace("Error -", "")

                    <<ObjErrorResponse is created here by assigning error message.>>

                    Return Json(ObjErrorResponse, JsonRequestBehavior.AllowGet)
                End Try

JQUERY Call

CommonJS.ShowProgress();
                CommonJS.ajaxPost(_Controller   "/Delete"
                    , 'json'
                    , { // dataParam // }
                    , function (msg) {
                        CommonJS.HideProgress();
                        var responseObj = msg;
                        if (responseObj.Success) {
                            if ((responseObj.Data) && typeof responseObj.Data === 'string') {
                                alert(responseObj.Data);
                            }
                            //Processing goes here 
                        }
                        else {
                            CommonJS.ShowErrors(responseObj);
                        }                        
                    }
                    , function (jqxhr, textStatus, error) {
                        CommonJS.HandleErrors(jqxhr);
                    }
                    , true
                );

When we browser MVC application URL on user machine (other than server machine) we are getting below behaviour

In case of Success; we are getting JSON correctly both on server machine and User machine.
In case of Exception raised we send JSON error Response which eventually shown some error message to user. - it working fine when we physically browse that MVC URL on server machine. However we get issue only on user machine it shows text/html as response in user browser. rather than application/json.

Couple of More Information from User machine.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/>
<title>500 - Internal server error.</title>
<style type="text/css">
<!--
body{margin:0;font-size:.7em;font-family:Verdana, Arial, Helvetica, sans-serif;background:#EEEEEE;}
fieldset{padding:0 15px 10px 15px;} 
h1{font-size:2.4em;margin:0;color:#FFF;}
h2{font-size:1.7em;margin:0;color:#CC0000;} 
h3{font-size:1.2em;margin:10px 0 0 0;color:#000000;} 
#header{width:96%;margin:0 0 0 0;padding:6px 2% 6px 2%;font-family:"trebuchet MS", Verdana, sans-serif;color:#FFF;
background-color:#555555;}
#content{margin:0 0 0 2%;position:relative;}
.content-container{background:#FFF;width:96%;margin-top:8px;padding:10px;position:relative;}
-->
</style>
</head>
<body>
<div id="header"><h1>Server Error</h1></div>
<div id="content">
 <div ><fieldset>
  <h2>500 - Internal server error.</h2>
  <h3>There is a problem with the resource you are looking for, and it cannot be displayed.</h3>
 </fieldset></div>
</div>
</body>
</html>

Expected Response:

{"Success":false,"Data":null,"Errors":[{"ErrorMessage":"Unable to peform Delete operation."}],"CustomData":{}}

CodePudding user response：

In addition to setting the status code, you'll need to set the TrySkipCustomIisErrors property on the response. Otherwise, IIS will see a 500 response and return its custom "internal server error" page instead of your own JSON response.