Outlook web attachment not open and can't download

Dear @Eranga Jayaweera,

From what you've described, you're currently unable to open or download email attachments in both Outlook Web and the new Outlook app. When you try to preview the file, you get a message saying the document preview couldn't be created. And when you try to download it instead, you get another error saying the request couldn't be completed. So right now, you're completely blocked from accessing your attachments either way.

To better assist, could you please confirm:

• Does this impact all users or only specific users?
• Does it happen with all attachments or only certain types (PDF, Word, Excel, etc.)?
• Does the issue happen in both Outlook on the web and the new Outlook app for the same user?
• Does it work when using a different browser or InPrivate/Incognito mode?
• Can users download attachments successfully from Classic Outlook (desktop app)?
• Have you tried accessing the attachment from a different browser or a different device?

In the meantime, I recommend some steps below:

1/ Browser isolation test

Open Outlook on the web in InPrivate/Incognito or other browsers.

Try opening/downloading the same attachment

2/ Try the same action using a different network (example: mobile hotspot)

Test the same action using a different network (for example, a mobile hotspot)

If it works on hotspot, it likely indicates a firewall/proxy/network restriction in the current environment

3/ Resend the attachment

Please ask the sender to resend the attachment, as the original file may have been corrupted during transmission

4/Temporary workaround (if urgent)

If Classic Outlook (desktop) works, users can download attachments there while we continue investigating the issue in Outlook on the web/new Outlook

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you. 

Thank you for your cooperation.

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