Trouble with Outlook 16.114 on MacOs 15.7.9

Engineering 20 Reputation points
2026-10-20T15:07:31.75+00:00

I am unable to attach any file using Outlook 16.114 on MacOs 15.7.9. Nothing will attach or upload to onedrive. Not sure where to start looking to resolve. Was having the same problem using the browser base version on Firefox until I updated it.

Outlook | MacOS | New Outlook for Mac | For business
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Kai-L 21,095 Reputation points Microsoft External Staff Moderator
2026-10-20T15:29:57.71+00:00

Hello Engineering,

As a forum moderator, I am not able to review your Outlook installation or account settings to diagnose and fix this directly. My role here is limited to providing general guidance you can apply from your side. Since the same problem in the web version went away after you updated Firefox, the desktop app may have a similar version‑related issue. I suggest trying the following:

  1. Update Outlook: Go to Help > Check for Updates and install any available updates, then restart your Mac.
  2. Test drag and drop: Drag a small file from Finder directly into a new message to see whether it attaches.
  3. Check permissions: In System Settings > Privacy & Security > Files and Folders, make sure Outlook is allowed to access your Desktop, Documents and Downloads folders if it is listed.

In the meantime, you can use Outlook on the web in your updated browser to send attachments.

If the problem continues, you can report it from Help > Contact Support in Outlook and include your Outlook and macOS versions and whether drag and drop also fails. This information will help Microsoft identify a possible regression.

For reference: Contact support within Outlook for Mac | Microsoft Support

I hope this helps. Looking forward to your reply.

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  1. Engineering 20 Reputation points
    2026-10-22T10:39:01.5633333+00:00

    After checking the versions and release notes, I cleared the cache and cookies, restarted and so far so good. Going to keep an eye on the situation since most applications are now being built to run on Mac Silicon Chips which apparently is geared differently than the older Intel chips.

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