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Outlook won't open: Cannot start Microsoft Outlook. The command line argument is not valid. Verify the switch you are using.

Anonymous
2023-11-13T20:02:13+00:00

Windows 11. Office 365. All updated.

Outlook won't open:

Getting message:

Cannot start Microsoft Outlook. The command line argument is not valid. Verify the switch you are using.

Maybe an add-in is causing a problem? But how do I start outlook to fix?

Can'start in safe mode. tried several times.

Outlook | Windows | Classic Outlook for Windows | For home

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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  1. Anonymous
    2023-11-14T04:11:25+00:00

    Dear Rod.Fowler,

    Good day! Thank you for posting to Microsoft Community. We are happy to assist you.

    Based on your description, you're having trouble with Outlook. This error message usually occurs when there is an issue with the command line argument that is being used to start Outlook.

    To fix this issue, you can try resetting the navigation pane in Outlook. Here are the steps to do that:

    1. Close Outlook if it is open.
    2. Press the Windows key + R to open the Run dialog box.
    3. Type "outlook.exe /resetnavpane" (without the quotes) and press Enter.
    4. Outlook should start normally now.

    If resetting the navigation pane doesn't work, you may need to repair your Office installation. You can do this by going to Control Panel > Programs and Features, selecting Microsoft Office, and clicking on Change. From there, select "Quick Repair" or "Online Repair" and follow the prompts.

    If the issue persists, would you plese try to download and re-install the newest version of Outlook via: Download and install or reinstall Microsoft 365 or Office 2021 on a PC or Mac - Microsoft Support. (Please make sure not installing multiple versions of Outlook in the same PC.)

    I hope this helps! If there is any update or I misunderstand you, please feel free to let me know. I will continue to assist you. Your understanding and co-operation are highly appreciated.

    Thanks for your precious time. Have a nice day.

    Sincerely,

    Sherry | Microsoft Community Moderator

    3 people found this answer helpful.
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  2. Anonymous
    2023-11-13T20:50:44+00:00

    i do not know what that means or how to fix it

    1 person found this answer helpful.
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  3. Anonymous
    2023-11-20T03:47:30+00:00

    It was this that finally allowed my Outlook to re-boot:

    If resetting the navigation pane doesn't work, you may need to repair your Office installation. You can do this by going to Control Panel > Programs and Features, selecting Microsoft Office, and clicking on Change. From there, select "Quick Repair"

    But I must ask; why Outlook was disabled from re-booting in the first place?

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  4. Anonymous
    2023-11-14T00:53:34+00:00

    Dear Rod.Fowler,

    Thank you for posting to Microsoft Community. We are happy to assist you.

    We are looking into your situation, we will update the thread shortly.

    Appreciate your patience and understanding and thank you for your time and cooperation.

    Sincerely,

    Sherry | Microsoft Community Moderator

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