Email Attachments disabled/greyed out - Unable to open or view file attachments in email - Outlook for Mac/Exchange

Question

Email Attachments disabled/greyed out - Unable to open or view file attachments in email - Outlook for Mac/Exchange

Jay Betito 0

Hi Support,

For the past few weeks we've had some users run into an issue with Outlook when opening meetings from a calendar that have file attachments. This is an intermittent issue of the file attachments being greyed out, unavailable, users being unable to open/view the attachments. I've assisted them with updating Outlook, restarts, also clean reinstalls of MS 365/Outlook desktop apps to no resolve. I've also tried the "Clear Application Data" option. Users are using Outlook for Mac on MacOS Golden Gate 27.2 & 27.2.1`, respectively. We've also tried toggled the internet/wifi off/on, also temporarily disabling the Security/AV + Firewall to no resolve. This seems to be localized to the Outlook Desktop App running on computers, as the users are able to open/view the file attachments on OWA - Outlook for web, and the Outlook mobile app on iOS.

Any suggestions or guidance on resolving this issue are appreciated.

Jay B.
IT Support Analyst

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2 answers

Your answer

Answer 1

Hi Jay Betito

I would recommend referring to A's response first, as it provides detailed guidance on collecting logs and escalating the issue to Microsoft if needed.

In addition to that, since the attachments can be opened successfully in Outlook on the web and Outlook for iOS, it may be helpful to determine whether the issue is tied to a particular calendar or mailbox scenario. For example:

Does the issue occur only in shared, delegated, or Microsoft 365 Group calendars, or also in users' primary calendars?
Does it affect existing meetings only, or can the behavior be reproduced with a newly created meeting that contains a test attachment?
Are all attachment types affected, or only certain file formats?
If another user opens the same meeting in Outlook for Mac, do they experience the same behavior?

Gathering these details may help identify whether the issue is related to a specific calendar type, meeting item, or Outlook for Mac client behavior before further escalation. Please feel free to share any findings.

Answer 2

Use Outlook on the web as the immediate workaround and report the reproducible Mac-only failure through Outlook’s Help > Contact Support, allowing log collection so Microsoft can investigate it as a potential current-client regression.

The same meeting attachments work in OWA and iOS, while reinstalling, clearing application data, restarting, changing networks, and disabling security controls did not help. That makes further repetition of those repairs low value. Microsoft’s current Outlook for Mac known-issues list does not identify this exact meeting-attachment symptom on macOS 27.2/27.2.1.^1^

Check the one matching documented defect

Microsoft previously fixed an Outlook for Mac issue where Preview, Open, Save As, and Remove were greyed out in the attachment menu. However, it specifically applied to legacy Outlook for Mac and was fixed in production build 16.90.3 (16.90.24110120).^2^

On one affected Mac, record Outlook > About Outlook:

If it is legacy Outlook and older than 16.90.3, that documented fix applies. Update beyond that build.
If it is New Outlook, or already later than 16.90.3, do not treat that historical issue as the resolution; proceed with escalation.
If all affected Macs share the same Outlook build/update channel, include that correlation in the case.

Microsoft AutoUpdate is available from Help > Check for Updates, and administrators can deploy the update packages through their existing software-deployment tooling.^3^ Since these Macs were already updated, this is a build-identification step rather than another generic update attempt.

Capture a minimal reproduction

Before opening the case, collect results from one affected meeting:

Record whether it is in the user’s primary, shared/delegated, or Microsoft 365 Group calendar.
Record whether the user is the organizer, delegate, or attendee.
Test both:
- An existing affected meeting.
- A newly created meeting with a small PDF or text attachment.
Record whether every attachment type is greyed out or only particular extensions.
Capture:
- Outlook version and build.
- New or legacy Outlook.
- macOS version.
- Screenshot or short recording of the greyed-out attachment controls.
- Meeting timestamp/subject with sensitive information removed.
- Confirmation that the identical item opens in OWA.

Calendar location matters because Outlook has separate documented limitations for attachments in Microsoft 365 Group calendars. For example, attached Outlook items are not retained in Modern Group Calendar meetings; Microsoft’s workaround is to upload the item to the group’s Files area or OneDrive for Business and place a link in the meeting body.^4^ That limitation applies only if the affected items match those conditions; it does not explain ordinary file attachments that remain accessible in OWA.

Submit the logs

On an affected Mac:

Open Outlook > Help > Contact Support.
Select Continue when prompted to permit Outlook log collection.
Describe the issue as: “Existing calendar meeting attachments intermittently show greyed-out Open/Preview controls in Outlook for Mac, but the same attachments open in OWA and Outlook for iOS.”
Attach the reproduction details above and start the conversation.^5^

For an education work/school tenant, the organization’s Microsoft 365 administrator can also open the service request through its normal Unified Support channel. Most users can additionally submit Help > Feedback > Report a Problem.^6^

Until Microsoft identifies the affected build or supplies a fix, continue opening those attachments through OWA; avoid weakening antivirus or firewall controls further because the tests already ruled out that path.

References