The request was aborted: Could not create SSL/TLS secure channel. RRS feed

  • Question

  • Goodmorning everyone!

    I built a simple applications that, when a certain input is received, makes a variable number of POST WebRequests to a specific API endpoint. This has always worked well, until yesterday: my application started throwing the following exception: The request was aborted: Could not create SSL/TLS secure channel.

    Dim BotID As String = “…”
    Dim Token As String = “…”
    Dim Users() As String   ‘this array was previously properly filled with user IDs
    For Each UserID As String In Users
         Dim Request As WebRequest = WebRequest.Create(“” & BotID & “/users/" & UserID & "/send?chatfuel_token=” & Token & “&chatfuel_message_tag=EVENT_UPDATE&chatfuel_block_name=AD&msgid=4555”)
         Request.Method = “POST”            
         Request.ContentType = “application/json”
         Dim Response As WebResponse = Request.GetResponse()
         Using dataStream = Response.GetResponseStream()
    	     Dim Reader As New StreamReader(dataStream)
    	     Dim ResponseBody As String = Reader.ReadToEnd()
         End Using    

    I did not change any code in my application, it just suddenly stopped working. If I try to make other WebRequests (with the same code) pointing to different endpoints, everything works well. This seems to be a problem just with that site. The site however does not have any problem with the certificate: it is valid and they use TLS 1.3 as well as TLS 1.2 (here you can see: while here you can see the analysis of a site that works with my application:

    I tried changing the version of the .NET framework. The version 4.7.2 was installed: I tried with both the 4.8 and the 4.7.1versions, but none of them worked.

    Please help me!

    Monday, August 12, 2019 5:28 PM

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