Wrong user mentions in Teams message using AdaptiveCard in an incoming Webhook

Question

Wrong user mentions in Teams message using AdaptiveCard in an incoming Webhook

Albert-Jan Verhees 0

I'm using an automated process that mentions team members in a message every day. I use the AdaptiveCard and see some unexpected behavior when Teams cannot mention a specific user. Somehow the replacements of the <at>XXXXX</a> with a user mention is completely shifted in the message. If I enter a correct user id for that user, all the mentions seem to be in the right place again.

It looks like Teams removes users from the list that cannot be found, but it still uses an index to resolve them in the message:

Let me explain with an example message:

{
  "type" : "message",
  "attachments" : [ {
    "contentType" : "application/vnd.microsoft.card.adaptive",
    "content" : {
      "version" : "1.0",
      "type" : "AdaptiveCard",
      "body" : [
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>XXXXX</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>me</at>",
          "wrap" : true
        } ],
      "msteams" : {
        "entities" : [
          {
            "type" : "mention",
            "text" : "<at>XXXXX</at>",
            "mentioned" : {
              "id" : "******@our-company.com", <-- Non-existing user
              "name" : "XXXXX"
            }
          },
          {
          "type" : "mention",
          "text" : "<at>me</at>",
          "mentioned" : {
            "id" : "******@our-company.com", <-- Existing user
            "name" : "Me"
          }
        }
        ],
        "width" : "Full"
      },
      "$schema" : "http://adaptivecards.io/schemas/adaptive-card.json"
    }
  } ]
}

Now the message is displayed like: User's image

Notice that the first mention has been replaced by the second user.

If I swap the order of the mentions in the request, it works fine:

{
  "type" : "message",
  "attachments" : [ {
    "contentType" : "application/vnd.microsoft.card.adaptive",
    "content" : {
      "version" : "1.0",
      "type" : "AdaptiveCard",
      "body" : [
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>XXXXX</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>me</at>",
          "wrap" : true
        } ],
      "msteams" : {
        "entities" : [
          {
            "type": "mention",
            "text": "<at>me</at>",
            "mentioned": {
              "id": "******@our-company.com", <-- Existing user
              "name": "Me"
            }
          },
          {
            "type": "mention",
            "text": "<at>XXXXX</at>",
            "mentioned": {
			  "id" : "******@our-company.com", <-- Non-existing user
              "name": "XXXXX"
            }
          }
        ],
        "width" : "Full"
      },
      "$schema" : "http://adaptivecards.io/schemas/adaptive-card.json"
    }
  } ]
}

And the message looks like this, as expected:
User's image

I think this is a bug.

Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-21T06:54:36.77+00:00

Thanks for raising your issue. We will check this at our end and will update you accordingly.

Prasad-MSFT 9,766 Microsoft External Staff Moderator

Update: We tried to replicate this issue using below JSON, however unable to repro the behaviour. The card renders as below
User's image
Card JSON

{
    "version": "1.5",
    "type": "AdaptiveCard",
    "body": [
        {
            "type": "TextBlock",
            "text": "Mention user: <at>Adele</at>"
        },
        {
            "type": "TextBlock",
            "text": "Mention user: <at>Me</at>"
        }
    ],
    "msteams": {
        "entities": [
            {
                "type": "mention",
                "text": "<at>Adele</at>",
                "mentioned": {
                    "id": "******@M365x41627585.onmicrosoft.com",
                    "name": "Adele Vance"
                }
            },
            {
                "type": "mention",
                "text": "<at>Me</at>",
                "mentioned": {
                    "id": "******@M365x41627585.onmicrosoft.com",
                    "name": "MOD Administrator"
                }
            }
        ]
    },
    "$schema": "https://adaptivecards.io/schemas/adaptive-card.json"    
}

Albert-Jan Verhees 0 Reputation points

2025-10-21T14:23:56.11+00:00

Thanks for testing. In your example, who is the unknown user? I also did the test with 3 mentions and can clearly see that the mentions have shifted when the second user is not resolved properly:
Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-22T06:23:10.2433333+00:00

Hi Albert-Jan Verhees, in my example the other user is a valid in-tenant user.
And could you please specify what do you mean by "user is not resolved properly", does it mean the second user in your case is an invalid user?
Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-30T12:05:05.48+00:00

Hi Albert-Jan Verhees, could you please specify what do you mean by "user is not resolved properly", does it mean the second user in your case is an invalid user?

2 answers

Your answer

Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-21T06:54:36.77+00:00

Thanks for raising your issue. We will check this at our end and will update you accordingly.
Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-21T11:24:48.17+00:00

Update: We tried to replicate this issue using below JSON, however unable to repro the behaviour. The card renders as below

Card JSON

{ "version": "1.5", "type": "AdaptiveCard", "body": [ { "type": "TextBlock", "text": "Mention user: <at>Adele</at>" }, { "type": "TextBlock", "text": "Mention user: <at>Me</at>" } ], "msteams": { "entities": [ { "type": "mention", "text": "<at>Adele</at>", "mentioned": { "id": "******@M365x41627585.onmicrosoft.com", "name": "Adele Vance" } }, { "type": "mention", "text": "<at>Me</at>", "mentioned": { "id": "******@M365x41627585.onmicrosoft.com", "name": "MOD Administrator" } } ] }, "$schema": "https://adaptivecards.io/schemas/adaptive-card.json" }
Albert-Jan Verhees 0 Reputation points

2025-10-21T14:23:56.11+00:00

Thanks for testing. In your example, who is the unknown user? I also did the test with 3 mentions and can clearly see that the mentions have shifted when the second user is not resolved properly:
Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-22T06:23:10.2433333+00:00

Hi Albert-Jan Verhees, in my example the other user is a valid in-tenant user.
And could you please specify what do you mean by "user is not resolved properly", does it mean the second user in your case is an invalid user?
Prasad-MSFT 9,766 Reputation points Microsoft External Staff Moderator

2025-10-30T12:05:05.48+00:00

Hi Albert-Jan Verhees, could you please specify what do you mean by "user is not resolved properly", does it mean the second user in your case is an invalid user?

Answer 1

Kudos-Ng 8,245 Microsoft External Staff Moderator

Hi Albert-Jan Verhees,

Thank you for posting your question in the Microsoft Q&A forum.

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

Based on the behavior you described and the accompanying JSON examples, I researched further through public resources and community discussions. Your hypothesis: “It looks like Teams removes users from the list that cannot be found, but it still uses an index to resolve them in the message” appears reasonable and does help explain the observed behavior.

To elaborate, if Teams indeed uses this rendering mechanism, the process likely works as follows:

Teams parses the <at> tags in the message body sequentially and maps them to the msteams.entities array by index.
When an entity cannot be resolved (e.g., invalid mentioned.id), that entity is dropped from the array, but the original <at> tag remains in the text.
As a result, subsequent valid entities shift forward and replace earlier <at> tags, causing the mismatch you observed.

To confirm this more precisely, you could test by sending three mentions where one in the middle is invalid and check whether the last two mentions shift positions.

Thank you again for providing such a clear description and JSON samples, this is extremely helpful for the community. For even greater impact, I encourage you to raise this feedback on the official Microsoft Feedback Portal so the product team can review and consider improvements to make the experience more consistent.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Albert-Jan Verhees 0

Thanks for the quick reply. I've added that test case below:

{
  "type" : "message",
  "attachments" : [ {
    "contentType" : "application/vnd.microsoft.card.adaptive",
    "content" : {
      "version" : "1.0",
      "type" : "AdaptiveCard",
      "body" : [
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>me</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>XXXXX</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>colleague</at>",
          "wrap" : true
        } ],
      "msteams" : {
        "entities" : [
          {
            "type": "mention",
            "text": "<at>me</at>",
            "mentioned": {
              "id": "******@our-company.com", <-- Existing user
              "name": "Me"
            }
          },
          {
            "type": "mention",
            "text": "<at>XXXXX</at>",
            "mentioned": {
              "id": "******@our-company.com", <-- Non-Existing user
              "name": "XXXXX"
            }
          },
          {
            "type": "mention",
            "text": "<at>colleague</at>",
            "mentioned": {
              "id": "******@our-company.com", <-- Existing user
              "name": "Colleague"
            }
          }
        ],
        "width" : "Full"
      },
      "$schema" : "http://adaptivecards.io/schemas/adaptive-card.json"
    }
  } ]
}

The card is:

User's image

As you can see the Colleague mention is shifted one up.

I have reported this in the Feedback Portal as you requested: https://feedbackportal.microsoft.com/feedback/idea/b8900e9d-52ab-f011-aa44-7c1e52e168a6

Kudos-Ng 8,245 Reputation points Microsoft External Staff Moderator

2025-10-17T12:15:05.88+00:00
Hi Albert-Jan Verhees,

Thank you for reviewing the previous answer and for adding this quick test case.

Your additional example clearly reinforces the earlier explanation.

To avoid this behavior in production, the best practice is to validate user existence before constructing the Adaptive Card. Ensure that:

Each <at> tag in the card text has a corresponding valid entity in msteams.entities.

Remove or replace any <at> tags for users that cannot be resolved, so the count and order remain consistent.

This approach prevents index misalignment and guarantees accurate rendering of mentions.

Thank you again for taking the time to report this behavior and provide such valuable insights for the forum. If possible, please consider marking the thread as Accepted Answer so the discussion can be highlighted and reach other community members who may encounter the same issue.
Albert-Jan Verhees 0 Reputation points

2025-10-17T12:19:48.6+00:00

@Kudos-Ng Thank you again for the quick reply.

Your suggestion can be a quick-fix for now. But is there an API on where I can resolve those users? From the client that sends these messages to the Webhook, there is no knowledge of whether or not the Teams user exists. It just uses the email address as user id as that is how users reside in our environment. If a user doesn't exist (yet/anymore), the mentions should still be placed correct order to avoid confusion on the ones mentioned in the message.
Kudos-Ng 8,245 Reputation points Microsoft External Staff Moderator

2025-10-17T13:05:31.5533333+00:00
Hi Albert-Jan Verhees,

Thanks for clarifying your scenario.

To better assist your scenario, could you share a bit more about your flow? Is this implemented as a standalone script or an app/service?

The reason I ask is that you can leverage the Microsoft Graph API to validate team membership before building the card. For example, the endpoint below returns all members of a specific team: GET https://graph.microsoft.com/v1.0/teams/{teamId}/members

reference: https://free.blessedness.top/en-us/graph/api/team-list-members?view=graph-rest-1.0&tabs=http

To call this API, you’ll need:

An access token obtained via Azure AD (OAuth 2.0).

Appropriate permissions (e.g., TeamMember.Read.All) granted to your app.

This way, you can confirm which users exist in the team and avoid index-shift issues when rendering mentions. If your process can’t currently acquire tokens, you might consider adding a lightweight service to handle the Graph call.
Kudos-Ng 8,245 Reputation points Microsoft External Staff Moderator

2025-10-20T10:26:41.4233333+00:00

Hi Albert-Jan Verhees,

Just checking in to see if you had a chance to review the previous response.

Your feedback would be very helpful in ensuring everything is on track.

Albert-Jan Verhees 0

I executed the test you requested. I've added this information earlier, but somehow it wasn't saved properly in this thread. That's why this answer might be a bit shorter.

Test request:

{ ....
   "body" : [
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>me</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>XXXXX</at>",
          "wrap" : true
        },
        {
          "type" : "TextBlock",
          "size" : null,
          "weight" : null,
          "text" : "Mention user <at>colleague</at>",
          "wrap" : true
        } ],
      "msteams" : {
        "entities" : [
          {
            "type": "mention",
            "text": "<at>me</at>",
            "mentioned": {
              "id": "******@our-company.com",
              "name": "Me"
            }
          },
          {
            "type": "mention",
            "text": "<at>XXXXX</at>",
            "mentioned": {
              "id": "******@eour-company.com",
              "name": "XXXXX"
            }
          },
          {
            "type": "mention",
            "text": "<at>colleague</at>",
            "mentioned": {
              "id": "******@our-company.com",
              "name": "Colleague"
            }
          }
        ],
        ....
}

The message in Teams:
User's image

As you can see, the third mention is shifted up.

In my actual use-case the "XXXXX" is an existing colleague, but somehow that email address is not resolved to this user. Maybe because it is an external account? We will look into that internally, but it doesn't change the behaviour of this bug as the mentions should still be in the right place.

Kudos-Ng 8,245 Reputation points Microsoft External Staff Moderator

2025-10-21T08:57:17.35+00:00
Hi Albert-Jan Verhees,

Thank you for sharing the additional context.

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

In your case, if “XXXXX” is an external or guest account, the email string may not match the actual UPN or Entra ID used internally, which explains why it wasn’t resolved.

Some common reasons include:

The user isn’t a member of the target Team or Microsoft 365 Group.

Guest accounts often have a different UPN format (#EXT# suffix).

Email vs. UPN mismatch or recent changes in directory.

Disabled, unlicensed, or pending provisioning states.

If you’ve verified that the user meets all conditions (exists, licensed, and is a team member) but the mention still fails, I highly recommend raising a support ticket via Microsoft 365 Admin Center or Azure Portal. Support agents can analyze backend logs and confirm whether this requires deeper analysis of your tenant configuration or escalation for further investigation if necessary.

Answer 2

Kudos-Ng 8,245 Microsoft External Staff Moderator

Hi Albert-Jan Verhees,

I noticed that Prasad mentioned earlier they couldn’t reproduce the issue in their environment, while you were able to. One detail that stood out: the Adaptive Card version Prasad used was 1.5, whereas your JSON shows 1.0.

As far as I know, the Adaptive Card version can matter in certain scenarios. So, one last suggestion: could you try updating your card to version 1.5 and retest the issue? This will help confirm whether the behavior is tied to the older rendering logic.

Let us know the outcome, it would be very useful for others following this thread.

Kudos-Ng 8,245 Reputation points Microsoft External Staff Moderator

2025-10-22T12:52:12.96+00:00

Hi Albert-Jan Verhees,

Just checking in to see if you had a chance to review the previous response.

Your feedback would be very helpful in ensuring everything is on track.

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Wrong user mentions in Teams message using AdaptiveCard in an incoming Webhook

2 answers

Your answer