VB .Net: Json not returning using ASHX - asp.net

Question

I'm having an issue with my code not returning Json response. I've never built an API using ASHX before. I have checked my Json string being created and it appears to be good.
The returned serialized json looks like this:
"{""Error"":""Error: Import: Unknown SKU Received!""}"
This is the correct message that should be returned. Instead I get Bad Request as a response. Not generating any errors on my code side.
Code Snippet:
Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim oImporter As Importer
Dim oResponse As Domain.Structures.Structures.ReturnResponse
Dim Input_sr As StreamReader
Dim sData As String
Dim bolError As Boolean = False
Dim obj As New Domain.Models.Order.Order
Dim sError As New order_response_error
Dim sResponse As New order_response_success
Try
Input_sr = New StreamReader(context.Request.InputStream)
sData = Input_sr.ReadToEnd
Input_sr.Close()
If context.Request.ContentType.StartsWith("application/json") Then
obj = JsonConvert.DeserializeObject(Of Domain.Models.Order.Order)(sData)
If obj.api_key = ConfigurationManager.AppSettings("api_key") Then
oImporter = New Importer(sData)
oResponse = oImporter.ImportOrder
context.Response.StatusCode = HttpStatusCode.OK
If oResponse.ReturnCode = "Error" Then
bolError = True
context.Response.StatusCode = HttpStatusCode.BadRequest
sError.Error = oResponse.ReturnCode + ": " + oResponse.Message
'sError.Error = String.Format(oResponse.ReturnCode, oResponse.Message)
Else
context.Response.StatusCode = HttpStatusCode.OK
sResponse.vendor_order_id = oResponse.Message
End If
Else
bolError = True
context.Response.StatusCode = HttpStatusCode.Unauthorized
sError.Error = "Error: Access Denied"
'sError.Error = String.Format("Error", "Access Denied")
End If
Else
bolError = True
context.Response.StatusCode = HttpStatusCode.BadRequest
sError.Error = "Error: Invalid content type"
'sError.Error = String.Format("Error", "Invalid content type")
End If
Catch ex As Exception
bolError = True
context.Response.StatusCode = HttpStatusCode.BadRequest
Utils.ErrorEmail("Order Error!", ex, AttachmentName:="Order.xml", AttachmentData:=sData)
sError.Error = String.Format("Error", ex.Message)
End Try
context.Response.ContentType = "application/json"
If bolError Then
context.Response.Write(JsonConvert.SerializeObject(sError))
Else
context.Response.Write(JsonConvert.SerializeObject(sResponse))
End If
End Sub
Error Response from client:
Error:
Cache-Control:
private
Content-Type: application/json; charset=utf-8
Server: Microsoft-IIS/10.0
X-AspNet-Version: 4.0.30319
X-SourceFiles: =?UTF-8?B?XFxhd2FyZGdyYXBoaWNzLmNvbVxkYXRhXFVzZXJzXG1ob2xtZXNcRGVza3RvcFxDb2xsYWdlXENvbGxhZ2VcQ29sbGFnZS5XZWIuUG9ydGFsXGFwaVx0ZXN0b3JkZXIxLmFzaHg=?=
X-Powered-By: ASP.NET
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods:
GET, POST, OPTIONS
Access-Control-Allow-Headers: X-Requested-With,Content-Type
Date:
Mon, 14 Oct 2019 14:47:57 GMT
Content-Length: 48 bytes
COMPLETE REQUEST HEADERS
pretty
Sec-Fetch-Mode: cors
Origin: chrome-extension://aejoelaoggembcahagimdiliamlcdmfm
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36
Content-Type: application/json
Accept: /
Sec-Fetch-Site: cross-site
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Cookie: AspxAutoDetectCookieSupport=1

Answer 1

You only have one place in your code where you return a custom message from the server, and with a 'BadRequest', on these lines:
context.Response.StatusCode = HttpStatusCode.BadRequest
sError.Error = oResponse.ReturnCode + ": " + oResponse.Message
That means your business logic is returning this (I can't say appropriately or not). You need to trace through the business logic to find the logic that is presenting the bad SKU message. From that point of view, the ASHX looks to be working correctly.