Cannot upload the file to dropbox when published on server - vb.net

Question

I'm trying to upload a file to dropbox. The file gets uploaded and code works when i'm running locally. But file never gets uploaded when published on the server. I'm having the following error .
Could not load type 'System.Security.Authentication.SslProtocols' from assembly 'System.Net.Primitives, Version=4.0.0.0, Culture=neutral, PublicKeyToken=*********'.
I'm trying the below code sample to upload it
public sub uploadtodropbox()
Using httpclient As New HttpClient
httpclient.Timeout = TimeSpan.FromMinutes(20)
Dim _DropboxClient = New DropboxClient(ApiKeyDropBox, config)
Dim resultstring As String = UploadToDB(_DropboxClient, dropboxdir, docName, fileBytes)
_DropboxClient.Dispose()
If Not resultstring = "RanToCompletion" Then
ErrorMsg &= "The following error occured: " & resultstring
End If
End Using
End Sub
and this is the funtion that is uploading to Dropbox
Private Function UploadToDB(_DropboxClient As DropboxClient, Directory As String, Filename As String, Content As [Byte]()) As String
Try
Dim result As String = "Unknown"
Dim trycnt As String = 0
Dim tryLimit As String = 20
Dim respnse As Task(Of FileMetadata)
Using _mStream = New MemoryStream(Content)
respnse = _DropboxClient.Files.UploadAsync(Convert.ToString(Directory & Convert.ToString("/")) & Filename, WriteMode.Overwrite.Instance, body:=_mStream)
While Not respnse.IsCompleted And trycnt < tryLimit
Threading.Thread.Sleep(1000)
trycnt += 1
result = respnse.Status.ToString()
End While
UploadToDB = result
End Using
End try
END function.
I have tried without using the httpclient then i am getting this error :
The type initializer for 'Dropbox.Api.DropboxRequestHandlerOptions' threw an exception.
Thank you

Answer 1

I go the answer . I have system.Net.primitives assembly that is creating a problem uploading the file to Dropbox. All i need to do is delete the reference and also the System.Net.Http has versions have been set wrong in the web.config file. Once i set that in the configuration everything works fine.
For the certificate I have set the on post back to validate and allow the certificates generated in the event handler.