I can not open outlook office 365

Hi, Joel Galvin

This usually happens because Office has saved an old sign-in, the password or account needs attention, or the Microsoft 365 activation information on the computer is damaged.

Here are some suggestions you can try:

Open a private browser window and sign in at Microsoft 365 on the web. Use the same email address and password you enter in Outlook. If this also fails, reset the password or contact your work or school IT administrator.

If the browser sign-in works, open Word or Excel, select File > Account, sign out of every listed account, close all Office apps, restart the computer, and sign in again with the account that owns the Microsoft 365 license.

On Windows, open Settings > Accounts > Email & accounts and Access work or school. Remove only old or unused accounts, then try again.

Run the Microsoft 365 sign-in troubleshooter and follow its instructions. It can automatically repair common Office sign-in problems.

If it still fails, please share the exact error message and whether the account is personal or provided by work or school.

Thank you for your patience in reading, I hope this information has been helpful to you. 

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