Hi @Brian Cordier
Thank you for posting your question in the Q&A Forum.
Since you can sign in on your mobile device, your account itself is working fine. The 0x0 error on Outlook for Mac usually indicates a conflict with local stored credentials or a synchronization glitch between the app and macOS.
Please follow these steps in order to resolve the issue:
1. Clear Cached Credentials
- Close Outlook completely.
- Open Keychain Access (Go to Applications > Utilities or press
Cmd + Space). - In the search bar, type "Microsoft" and then "Office".
- Select and Delete all entries related to your account and Microsoft Office identities.
- Restart Outlook and try to sign in again.
2. Reset the Account Connection
- In Outlook, go to the Outlook menu > Tools > Accounts.
- Select your education account and click the minus (-) button to remove it.
- Click the plus (+) button to add it back. Make sure to select Microsoft 365 when prompted for the account type.
3. Switch to Legacy Outlook
- If the error persists, go to the Help menu and select Revert to Legacy Outlook.
- Try signing in there. If it works, you can switch back to New Outlook afterwards to see if the connection holds.
If these steps don’t work, it’s possible that a Conditional Access policy from your school is blocking the sign-in. In that case, your Mac might need to be registered or meet specific security requirements before sign-in is allowed. Let us know how it goes!
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