exchange 365 admin 404 error

sim3vi 166 Reputation points

In an Hybrid exchange environment when I try to connect to Admin Exchange 365 I get this error:
Server Error in '/' Application.
The resource cannot be found.
Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.

Requested URL: /SignInError
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3930.0

I change browser, change user but the error is the same.
The users mailbox on 365 works. I can connect through powershell.

Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
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  1. JimmySalian-2011 41,916 Reputation points

    Hi Sim,

    Not sure what URL you are trying but can check this admin console -

    or the classic one


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  2. KyleXu-MSFT 26,206 Reputation points


    Do you receive this error when you click the “Office 365” tab from the Exchange on-premises admin center?

    This one has been changed earlier. I would suggest you update Exchange server to the lasted version first.

    If you want to access Exchange online admin center, it is suggested to access from this link directly.

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  3. JimmySalian-2011 41,916 Reputation points

    Glad to know it works, could be a temporary glitch. You can always check the status of Azure Service over here status

    Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

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  4. Amit Singh 4,846 Reputation points

    A couple of things to try

    • Make sure there is not a duplicate site in IIS that is capturing the request
    • Restarting IIS is never a bad option
    • Make the web.config itself set to target framework 4.0 and not 2.0

    Usually, when this happens where it works fine locally but not when deployed, it always turns out to be the third item, a web.config configuration mismatch. I hope this helps!

    Also, check this similar thread for help -

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  5. maih 20 Reputation points


    impossible d'ouvrir l'outil exchange admin center.

    Message d'erreur :

    Erreur HTTP 404.0 - Not Found

    La ressource que vous recherchez a été supprimée, a été renommée ou est provisoirement indisponible.

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