Getting 2400 error in outlook application

Anonymous
2023-04-11T09:25:43+00:00

Hi,

Something went wrong [2400] error in outlook application. Web outlook is working fine.

Tried outlook repair, reinstallation, new profile creation and cleared password from device credential manager still issue persist. Seems like Microsoft issue. Screenshot attached

Please share any troubleshooting steps for permanent fix

Thanks

Anand

Outlook | Windows | Classic Outlook for Windows | For home

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  1. Anonymous
    2023-04-25T19:15:37+00:00

    same problem here. started appearing today. super mega bad. after a couple of tries I got this email

    You need an app password
    We noticed that you tried to sign in with the password for your Microsoft account on one of these apps or devices. Since you've turned on two-step verification for ***@outlook.com, you need to use an app password instead for any of the following to work with two-step verification. We've sent this reminder to all the security info you've provided. If you haven't already done this, we'll help you set up these apps and devices with app passwords:
    <ul><li><p data-prewrap="true">Outlook desktop app for your PC or Mac</p></li><li><p data-prewrap="true">Email apps on an iOS, Android or BlackBerry device</p></li><li><p data-prewrap="true">Office 2010, Office for Mac 2011, or earlier</p></li><li><p data-prewrap="true">Windows Essentials (Photo Gallery, Movie Maker, Mail)</p></li><li><p data-prewrap="true">Zune desktop app</p></li><li><p data-prewrap="true">Xbox 360</p></li><li><p data-prewrap="true">Windows Phone 8 or earlier</p></li></ul>

    Obviously something broken on MS side as this wasn't necessary before.

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  2. Anonymous
    2023-04-25T13:58:56+00:00

    This is happening to me too!

    Driving me crazy and do not know what to do

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  3. Anonymous
    2023-04-25T11:15:12+00:00

    Yes, it's definitely something to do with the authorisation process. I've had 2FA implemented for a long time. Never been a problem till today. :(

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  4. Anonymous
    2023-04-25T10:55:23+00:00

    Same for me. Started today. Coincides with the forced 2FA adoption

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  5. Anonymous
    2023-04-25T08:41:50+00:00

    Hello. I've started getting this exact same problem this morning (25th April UK) Only affecting my outlook,com address in M365. Fine via web browser. Hasn't updated since sometime on Sunday 23rd.

    I've tried the suggestions here but nothing fixes the problem yet.

    FYI - also working fine on Android 11 phone

    Need assistance. TIA.

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