How to fix my college email so that I can login to Microsoft Excel.

Tri Tran (student) 0 Reputation points
2026-09-04T03:04:49.9733333+00:00

Hello,

I'm having trouble logging into the Microsoft Excel desktop app on my MacBook Air. When I enter my college email address, I receive the error shown in the attached screenshot. My professor has advised that students should have full access to Microsoft Office through our college email without needing a separate paid subscription. For context, I am able to log in successfully with my college email on both the Excel mobile app and the Excel web version, where I can create, edit, and save spreadsheets without issue. However, the web version is much less convenient for tasks like formatting tables and creating graphs, so I would prefer to use the desktop app instead. Additionally, when I save a file through the web version and then try to open it in the desktop app on my MacBook, it prompts me to log in again, and I run into the same error as before. Could you help me understand why the desktop app isn't accepting my login even though the web and mobile versions work fine? I would appreciate any troubleshooting steps or guidance to resolve this.

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Microsoft 365 and Office | Install, redeem, activate | For education | MacOS
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  1. Jade Ng 15,480 Reputation points Microsoft External Staff Moderator
    2026-09-04T03:58:10.4666667+00:00

    Dear Tri Tran (student),

    Based on your description, it appears that your college account is functioning correctly, as you are able to sign in and use Excel on both the web and mobile versions.

    First, could you please verify whether your college account includes a Microsoft 365 license that allows use of the desktop Office applications?

    1. Visit this link: https://portal.office.com/account/?ref=Harmony
    2. Once signed in, navigate to the Subscriptions section
    3. There, you should be able to view details related to your active Office 365 plan.

    This page will show you information such as your subscription type, billing status, renewal date, and any linked licenses.

    The error shown in your screenshot, AADSTS900561: "The endpoint only accepts POST requests. Received a GET request," is typically related to cached credentials, authentication tokens, or browser-related sign-in components on the Mac become corrupted.

    Next, please try these troubleshooting steps below:

    1.Completely sign out of all Microsoft apps

    • Open Excel, Word, or PowerPoint.
    • Click Sign Out
    • Quit all Office applications.
    • Restart your Mac.
    • Then try signing in again.

    2.Clear Microsoft credentials from Keychain

    • Open Keychain Access.
    • In the search box, search for: Microsoft/Office/ADAL/OneAuth
    • Delete Microsoft Office-related identity and token entries.
    • Restart the Mac.
    • Launch Excel and sign in again.

    3.Check Safari privacy settings

    • Open Safari.
    • Go to Settings > Privacy.
    • Temporarily disable: Prevent Cross-Site Tracking
    • Close Safari and retry signing in.

    4.Try update both macOS and Office

    5.Remove and reinstall Office

    If cached authentication components are damaged, please:

    • Uninstall Microsoft 365 apps.
    • Restart the Mac.
    • Download the latest Microsoft 365 installer through your college portal.
    • Install and try again.

    For reference, please visit:

    Hope this helps. Welcome to share any updates when you have time if you need further help on this issue. Thank you very much for your valuable time and your cooperation.


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