new outlook Adobe can't open

Telman Garakishiyev 0 Reputation points
2026-10-01T10:56:29.52+00:00

Dear Microsoft Support,

We are experiencing an issue with New Outlook where users are unable to open PDF attachments directly from emails.

We have already tried the following troubleshooting steps:

  1. Closed Outlook completely.
  2. Checked the following directory: %userprofile%\AppData\Local\Microsoft\OLK
  3. Confirmed that the Attachments folder already exists.
  4. Renamed the existing Attachments folder to Attachments_old.
  5. Restarted Outlook and tested the PDF attachment again.

However, the issue still persists.

Could you please investigate this issue and advise us on the recommended solution?

Thank you for your assistance.

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Outlook | Windows | Classic Outlook for Windows | For business
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  1. Helen Luu 3,300 Reputation points Independent Advisor
    2026-10-01T11:53:57.8366667+00:00

    Hello @Telman Garakishiyev

    As you mentioned that you are using Adobe to open the PDF files, could you please help me with the following information so I can better understand the issue?

    • Have you tried opening the PDF file using Outlook on the web? If so, does the PDF open successfully there?
    • I noticed that your post is tagged with Classic Outlook. Have you also tested the same PDF file in New Outlook while using Adobe as the default PDF viewer?
    • Which version of Classic Outlook are you currently using?
    • When did the issue first start occurring?
    • If you download the PDF file locally, are you able to open it successfully using Adobe Reader or a web browser (such as Microsoft Edge)?

    The answers to these questions will help determine whether the issue is related to Outlook, the PDF file itself, or the PDF viewer being used.

    I look forward to your update.

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  2. AI answer

    2026-10-01T10:57:02.02+00:00

    Since the Attachments folder already exists and recreating it did not help, use these checks next:

    1. Test the same PDF in Outlook on the web.
      • If it opens there, the issue is more likely isolated to the New Outlook desktop client.
    2. Try saving the attachment instead of opening it directly.
      • In Outlook, use the attachment drop-down and select Save As.
      • Attachments are saved to the Documents folder by default unless a different location is chosen during save.
      • If the file saves successfully but does not open directly from the message, that points to an attachment-opening issue rather than a download issue.
    3. Verify the default PDF app in Windows.
      • Outlook uses the Windows default app to open or preview many attachment types.
      • If PDF files are expected to open in Adobe, make sure Adobe Acrobat Reader is the default PDF viewer in Windows.
    4. If the problem is with previewing PDFs in Outlook, check for the known PDF previewer causes:
      • Confirm Adobe Acrobat Reader and Outlook Desktop use the same bitness: both 32-bit or both 64-bit.
        • In Outlook: File > Office Account > About Outlook.
        • In Adobe Acrobat Reader: Help > About Adobe Acrobat Reader.
      • If the bitness is different, uninstall the current Adobe Reader and install the version that matches Outlook.
      • If Microsoft PowerToys is installed, open PowerToys > File Explorer Add-ons and disable Enable PDF (.pdf) preview.
    5. If this is Classic Outlook rather than New Outlook, verify attachment preview settings:
      • File > Options > Trust Center > Trust Center Settings > Attachment Handling.
      • Make sure Turn off Attachment Preview is not enabled.
      • Select Attachment and Document Previewers and confirm the PDF previewer is enabled.
    6. If direct open still fails in New Outlook, use the current workaround:
      • Download or save the PDF first, then open it from Windows with the default PDF application.
    AI-generated content may be incorrect. Read our transparency notes for more information.

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