Forbidden/UnknownError when importing hosted contents #14138
Description
Steps to reproduce
I'm following the steps in https://learn.microsoft.com/en-us/microsoftteams/platform/graph-api/import-messages/import-external-messages-to-teams#step-3-import-messages and https://learn.microsoft.com/en-us/graph/api/channel-post-messages?view=graph-rest-beta&tabs=http#example-3-import-messages-with-inline-images to import hosted content to 1:1 chat and existing channels.
following are the steps:
Start migration
$groupId="**************"
$channelId="19:**************@thread.tacv2"
#start migration
$uri = "https://graph.microsoft.com/beta/teams/$groupId/channels/$channelId/startMigration"
$body=@{
"conversationCreationDateTime" = "2022-05-27T18:10:26.968Z"
} | ConvertTo-Json
$response = Invoke-RestMethod -Uri $uri -Headers $headers -Method Post -Body $body
Import message. Worked
$uri = "https://graph.microsoft.com/beta/teams/$groupId/channels/$channelId/messages"
$body = @{
body = @{
contentType = "html"
content = "This is an imported message."
}
createdDateTime = "2025-12-02T18:10:26.968Z"
from = @{
user = @{
id = "**********"
displayName = "John Doe"
userIdentityType = "aadUser"
}
}
} | ConvertTo-Json -Depth 5
$response = Invoke-RestMethod -Uri $uri -Headers $headers -Method Post -Body $body
Import message with hosted content. Failed.
$hostedBody = @{
body = @{
contentType = "html"
content = '<div><img src="../hostedContents/1/$value"></div>'
}
hostedContents = @(
@{
"@microsoft.graph.temporaryId" = "1"
contentBytes = "iVBORw0KGgoAAAANSUhEUgAAAAgAAAAIAQMAAAD+wSzIAAAABlBMVEX///+/v7+jQ3Y5AAAADklEQVQI12P4AIX8EAgALgAD/aNpbtEAAAAASUVORK5CYII="
contentType = "image/png"
}
)
createdDateTime = "2025-12-01T18:10:26.968Z"
from = @{
user = @{
id = "**********"
displayName = "John Doe"
userIdentityType = "aadUser"
}
}
} | ConvertTo-Json -Depth 10
$response = Invoke-RestMethod -Uri $uri -Headers $headers -Method Post -Body $hostedBody -ErrorAction Stop
I got the following error:
{
"error": {
"code": "Forbidden",
"message": "UnknownError",
"innerError": {
"date": "2026-02-24T02:48:50",
"request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5",
"client-request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5"
}
}
}
Expected behavior
Message posted with no error
Actual behavior
I got an error:
{
"error": {
"code": "Forbidden",
"message": "UnknownError",
"innerError": {
"date": "2026-02-24T02:48:50",
"request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5",
"client-request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5"
}
}
}
Error details
{
"error": {
"code": "Forbidden",
"message": "UnknownError",
"innerError": {
"date": "2026-02-24T02:48:50",
"request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5",
"client-request-id": "5b5784bc-504d-4b38-b6d6-0edce12575b5"
}
}
}