[Solved] Teams Incoming Webhook: Bad payload received by generic incoming webhook

Jenkins 55 Reputation points


We use the MessageCard Reference (https://learn.microsoft.com/en-us/outlook/actionable-messages/message-card-reference) to send messages to Teams via incoming webhooks (https://learn.microsoft.com/en-us/outlook/actionable-messages/send-via-connectors#send-the-message). Here is an example of a payload:

    "@type": "MessageCard",
    "@context": "http:\/\/schema.org\/extensions",
    "themeColor": "d58200",
    "title": "title",
    "text": "text",
    "potentialAction": [
            "@type": "OpenUri",
            "name": "Name",
            "targets": [
                    "os": "default",
                    "uri": "https:\/\/www.example.com\/"

We've been sending this for years, but since around 7th July we started getting the error message:

{"message":"Bad payload received by generic incoming webhook.","http_code":400}

I can also see the following response when making a request to the webhook endpoint:

System.ArgumentNullException: Value cannot be null. (Parameter 'jtoken')

This doesn't happen when I make the call (using the same endpoint and payload) using Postman. This only happens when we make the call from inside our code.

Does anyone know if anything has changed or why we would be getting this? I can't find any reference for the jtoken parameter. Our code hasn't changed.


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  1. Jenkins 55 Reputation points

    Our code makes a curl request. It's worked for years and then suddenly stopped. I added the following header to the request and it started working again:

    Content-Type: application/json

    11 people found this answer helpful.

  2. Ran Hou-MSFT 7,080 Reputation points Microsoft Vendor


    Based on your description, this problem is related to Teams script development, which we do not support. So we will add Microsoft Teams development tag to your thread.

    Thanks for your understanding and patience!

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