问题
I work on an application that as part of one of its features attaches files to outgoing emails with Office.context.mailbox.item.addFileAttachmentAsync. In the most recent update Outlook for Windows Version 1811 (Build 11029.20079 Click-to-Run) the files are failing to attach to the mailbox item with a "Download Error" displayed in the UI.
To inspect this further I user Fiddler and discovered that this method has started appending the following header Authorization: Bearer. Since no header authorization has been provided, this conflict causes trouble with the S3 service and a 400 error Only one auth mechanism allowed; is returned which would cause the download to fail.
Is there a workaround to this problem?
回答1:
@Kevin Kerr, thanks for reporting this issue.
This is a known issue that reproduces outside of our API. You can reproduce this by manually attaching this item to an e-mail: Open a new e-mail, click on Attach File, then click on Browse This PC..., and then copy/paste the URL of the file into the File name field of the Insert File dialog that opens up.
This issue also reproduces with Azure Blob Storage, so the best workaround is to host the files elsewhere.
We have engaged the appropriate team to address this issue, however, we don't have an ETA for the fix.
来源：https://stackoverflow.com/questions/53586742/addfileattachmentasync-appends-invalid-authorization-header