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Outlook for macOS crashing at startup

Mattia Gentilini 0 Reputation points
2026-05-29T07:55:15.61+00:00

I'm currently unable to run Outlook on my macOS, it crashes almost immediately when clicking the app icon.

Below is the full crash report that macOS shows after the cras-----------------------------------1

[Moderator note: personal info removed]

Outlook | MacOS | New Outlook for Mac | For business
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  1. Michelle-N 16,880 Reputation points Microsoft External Staff Moderator
    2026-05-29T08:47:18.6533333+00:00

    Please note that Q&A forum is a public platform, and moderators will modify the question to hide personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

    Hi @Mattia Gentilini

    Based on the information you provided, I understand that your Outlook for macOS is crashing immediately upon startup whenever you click the app icon, making it completely unusable.

    To better assist you and isolate the root cause, could you please share where you originally downloaded Outlook from?

    If you installed it directly from the Mac App Store, please try uninstalling the current version and then reinstalling version 16.107.x using the official links provided by Microsoft to see if you can successfully access Outlook again.User's image

    Reference: Update history for Office for Mac

    If the application continues to crash after the reinstall, could you please provide a few more details?

    • What type of email account are you trying to configure (e.g., Exchange, Microsoft 365, IMAP, or POP)?

    Please let me know how the reinstallation goes and share any updates!

    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".  

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  2. AI answer

    2026-05-29T07:55:35.9933333+00:00

    The crash report shows Outlook is terminating at launch because a required framework cannot be loaded:

    Library not loaded: @rpath/CocoaUI.framework/Versions/A/CocoaUI

    This is the same class of issue as the documented Outlook for Mac startup crash when a required framework inside the app bundle cannot be found due to file or bundle layout problems. In such cases, the Outlook application bundle is effectively broken and must be repaired or replaced.

    Use these steps to repair the installation and related Office components:

    1. Fully remove the current Office/Outlook apps
      1. Quit all Office apps.
      2. Open Finder → Applications.
      3. Use Command+click to select all Microsoft 365/Office apps (Outlook, Word, Excel, PowerPoint, OneNote, etc.).
      4. Ctrl+click the selection and choose “Move to Trash”.
    2. Remove Office data and licensing containers
      1. In Finder, on the menu bar select Go → Go to Folder…
      2. Enter ~/Library/Containers/.
      3. Move to Trash the folders that start with:
        • com.microsoft.Word
        • com.microsoft.Excel
        • com.microsoft.Powerpoint
        • com.microsoft.Outlook
        • com.microsoft.OneNote
      4. Go back to ~/Library and open Group Containers.
      5. If present, move these to Trash:
        • UBF8T346G9.ms
        • UBF8T346G9.Office
    3. Reinstall Office/Outlook cleanly
      1. Sign in to the Microsoft account dashboard associated with the subscription or license.
      2. From the services/products page, download and install Office/Outlook again.
    4. Update Outlook and macOS
      • After reinstalling, open any Office app.
      • Go to Help → Check for Updates and install all available updates. This mitigates known Outlook for Mac stability issues.
      • Ensure macOS is fully updated using Apple’s software update mechanism.
    5. If Outlook still crashes at startup
      • If the crash persists even after a clean reinstall and update, use Outlook on the web as a temporary workaround.
      • Then, from Outlook for Mac (if it opens at all) use Help → Contact Support, or use Microsoft 365 support channels, and provide the crash report so support can investigate the missing CocoaUI.framework on the specific macOS build.

    These steps align with the documented guidance for Outlook for Mac startup crashes caused by missing or mis‑packaged frameworks and general stability issues.

    References:

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