graph api broken: unable to retrieve item attachment from a calendar event

Question

Hi there,

I used attachment api (GET events/{id}/attachments/{id}?$expand=microsoft.graph.itemAttachment/item) for downloading item attachments from calendar events.

It worked well until few weeks ago(not sure the exact time, I just found the error this weekend).

It returns a sever error(status code: 500) An internal server error occurred. The operation failed., Index was outside the bounds of the array..

It looks like that the Microsoft develop team has changed the behavior (looks like a bug) without mentioning it in the changelog and documents.

I would appreciate any insights or guidance on resolving this issue.

Thanks.

some documents:

https://learn.microsoft.com/en-us/graph/api/resources/itemattachment?view=graph-rest-1.0

https://learn.microsoft.com/en-us/graph/api/attachment-get?view=graph-rest-1.0&tabs=http

Answer 1

I can confirm this.

I tested with https://developer.microsoft.com/en-us/graph/graph-explorer

---

Mail 1 - Attachment = Mail

"@odata.type": "#microsoft.graph.itemAttachment",

https://graph.microsoft.com/v1.0/users/test@company.com/mailFolders/Inbox/messages/AAM..( MessageID)...9AAA=/attachments/AAMk..(AttachmentID)..AZT8=/$value

Result: get the raw mail successfully

---

Mail 2 - Attachment = Apoinment

"@odata.type": "#microsoft.graph.itemAttachment",

https://graph.microsoft.com/v1.0/users/test@company.com/mailFolders/Inbox/messages/AAX..( MessageID)...7AAA=/attachments/AAXk..(AttachmentID)..BK3=/$value

or

https://graph.microsoft.com/v1.0/users/test@company.com/mailFolders/Inbox/messages/AAX..( MessageID)...7AAA=/attachments/AAXk..(AttachmentID)..BK3=?$expand=microsoft.graph.itemAttachment/item

Result:

{
    "error": {
        "code": "ErrorInternalServerError",
        "message": "An internal server error occurred. The operation failed., Index was outside the bounds of the array."
    }
}