AADSTS90015: Requested query string is too long. error message on Mac when accessing teams via MS 365

Dear @Sophia Adams Bhatti,

Thank you for reaching out and I’m sorry to hear that you’re encountering this sign-in issue when accessing Microsoft Teams on your Mac. I understand how disruptive this can be, especially when it prevents you from using Teams as expected.

Based on the error message AADSTS90015: “Requested query string is too long”, this behavior is typically related to a sign-in session issue. In most cases, it occurs when the browser or authentication process contains excessive or corrupted cached data (such as cookies), which interferes with the Microsoft 365 sign-in flow.

In this case, I would recommend trying the following steps:

1.Sign out of all Microsoft accounts in your browser (both work and personal accounts).

2.Clear browser cookies and site data:

• Go to the Safari app on your Mac.
• Choose Safari > Settings, then click Privacy.
• Click Manage Website Data.
• Select one or more websites, then click Remove or Remove All.

3.Close your browser completely, reopen it, and then sign in again using only your work account via the Microsoft 365 portal.

If the issue persists, please try accessing Teams using an InPrivate/Incognito window or a different browser.

If you are using Safari, you may also try temporarily disabling the “Prevent cross-site tracking” setting.

Should the issue continue after these steps especially if it occurs across multiple browsers or devices, it may indicate a configuration-related issue within your organization’s sign-in setup. In that case, please let me know so I can assist you further or guide you on next steps.

Thank you for your patience and understanding. I wish you a great day and send you my best regards.

Looking forward to your response!

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