Attachments with special characters lost when uploaded from MS Teams

[LuisM000]

Version

Lastest

Describe the bug

When I upload an attachment from Microsoft Teams with certain special characters, such as a '+', the attachment "disappears" when it is received in the bot's backend.

For example, uploading a file with a "normal" name like test.txt works as expected, and I receive the following in the bot's backend:

{
    "attachments": [
        {
            "contentType": "application/vnd.microsoft.teams.file.download.info",
            "content": {
                "downloadUrl": "https://ckm-my.sharepoint.com/personal/xxxxxx/_layouts/15/download.aspx?UniqueId=xxxxx-xxxx-xxxx-xxxx-xxxxx&Translate=false&tempauth=v1.xxxx.xxxx.xxxx&ApiVersion=2.0",
                "uniqueId": "xxxx-xxxx-xxxx-xxxx-xxxxx",
                "fileType": "txt"
            },
            "contentUrl": "https://ckm-my.sharepoint.com/personal/xxxxxx/Documents/Microsoft Teams Chat Files/test.txt",
            "name": "test.txt"
        },
        {
            "contentType": "text/html",
            "content": ""
        }
    ],
    "type": "message",
    "timestamp": "2024-07-11T10:29:11.4680572Z",
    "localTimestamp": "2024-07-11T12:29:11.4680572+02:00",
    "id": "1720693751445",
    "channelId": "msteams",
    // ....
}

However, if I upload a file with a name like test+.txt, I only receive the following:

{
    "attachments": [
        {
            "contentType": "text/html",
            "content": ""
        }
    ],
    "type": "message",
    "timestamp": "2024-07-11T10:36:45.0287287Z",
    "localTimestamp": "2024-07-11T12:36:45.0287287+02:00",
    "id": "1720694205007",
    "channelId": "msteams",
    //...
}

To Reproduce

Steps to reproduce the behavior:

1. Use the basic example from BotBuilder-Samples.
2. Upload a file with a normal name (e.g., test.txt) from Microsoft Teams.
3. Observe the attachment received in the bot's backend.
4. Upload a file with a special character in the name (e.g., test+.txt) from Microsoft Teams.
5. Observe the attachment received in the bot's backend.

Expected behavior

Attachments with special characters in their names should be processed correctly and received in the bot's backend just like attachments with normal names.

Screenshots

N/A

Additional context

This issue has also been posted on Stack Overflow.

[rliberoff]

I also have this very same issue.
We cannot control the name of the files the user's upload from Teams to the bot's backend.
Please help!

[MarioRamosEs]

Same issue here :(

[dmvtech]

I can reproduce. As it is happening on the Teams side (before even getting to the bot), I am investigating on where/how to have this handled.

[marsanga]

Hello there! Are there any news on this?

[rliberoff]

Is there a ETA or update on this issue?

[ceciliaavila]

Hi @tracyboehrer, this is the same issue reported in #4750. It's on MS Teams' side, the bot is not receiving the attachment when there are special characters in its name.

[tracyboehrer]

OP should refer this to the Teams Samples or Teams AI SDK repo.