Thank you for reaching out to Microsoft Q&A forum.
I understand this can be very frustrating, especially since everything was working normally before. Please try the steps below in order, and check an attachment after each step:
Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.
1. Open Outlook.com in a Private/Incognito window
- This helps rule out stored browser data that may affect how attachments open. Sign in again and try the attachment.
2. Clear Safari data for Outlook only
- On Safari, clear website data related to outlook and live, then sign in again and retry the attachment.
3. Allow pop‑ups for Outlook.com
- Attachments may open in a new tab or window, which Safari can block by default.
4. Temporarily disable Safari extensions or content blockers
- Some extensions can prevent attachments from opening correctly.
5. Download the attachment instead of opening it
- Choose Download/Save, then open the file from the Downloads folder (PDFs usually open with Preview).
However, if the steps above do not resolve the situation, you may try opening Outlook.com in a different browser, such as Chrome or Edge, or use the Outlook application to view the attachments.
Please feel free to let me know if you have any further updates, thanks.
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