Searched till my fingers bled; gave up and installed the free "Windows Outlook", but it was a mess that clear Outlook credentials manager I can't take. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Windows 10 will reach EOS (end of support) on October 14, 2025.

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If you have an issue that's not listed in this article, go to Outlook data file cannot be accessed the following Microsoft TechNet wiki page. The wiki page lists other known issues and workarounds. Since Microsoft recently demanded OAuth2 authentication, I've been trying everything I found here and at Microsoft, but every 'help' webpage to setup Hotmail and Thunderbird seem badly outdated. If the error you are encountering is not listed, please create a ticket on our Email and Calendar Help page for assistance. If memory serves me right, modern auth with 2fa, and being a GA and using the account for outlook are known for issues. So, it looks like the version of Outlook that I have won’t play nice with Modern Authentication.

Troubleshoot sign-in issues with Office modern authentication when you use AD FS

The currently configured authentication methods can remain unchanged. For example, if Windows Integrated Authentication is configured as the primary authentication method, it can remain configured this way. Login to server outlook.office365.com with username [Duck ID]@uoregon.edu failed. Once your account has Modern Authentication enabled, you can no longer pull your UO email into Gmail and/or reply from Gmail on behalf of your UO account. This page contains information on what errors may come up when setting up your email with Modern Authentication (Modern Auth), and what steps are needed to resolve them.

Gmail

• If the error you are encountering is not listed, please create a ticket on our Email and Calendar Help page for assistance.
• To resolve this issue, set up AD FS to use forms-based authentication as the secondary form of authentication.
• Additionally, accessing email through a web client will continue to work, even if an application is having issues.
• They suggested clearing credentials, which I have already tried.
• If it continues to be problematic, you may need to either a.) Remove any related credentials from the users credential manager in Control Panel, it b.) Create a new outlook profile.
• I have confirmed that on two different PCs that are accessing the same mailbox with the same version of Outlook, which is the latest version from Microsoft included within my Office 365 package.

I have a couple of PCs that access the system on the same account from Win 10. Both are affected in the same way in that Outlook is constantly asking for a username & password ( not using the modern authentication dialogue box ). I’ve tried various registry changes that I’ve found from Googling, tried changing the password, tried re-installing Office and also enabling & disabling MFA. Microsoft will soon phase out Basic Authentication and replacing it with Modern Authentication.

iOS Mail

I have confirmed that on two different PCs that are accessing the same mailbox with the same version of Outlook, which is the latest version from Microsoft included within my Office 365 package. If it continues to be problematic, you may need to either a.) Remove any related credentials from the users credential manager in Control Panel, it b.) Create a new outlook profile. We will never ask you to call or text a phone number or share personal information.





I’m going to try & switch modern authentication off to see if that is Outlook OST vs PST repair the issue, although there doesn’t seem to be any way of doing this. It does look llike a one-time thing to switch it on. I’m quite fortunate that this is just my O365 instance, so customers not being impacted. Desktop SSO is the process that's used to obtain seamless sign-in to Microsoft 365 resources through AD FS from a domain-joined computer that's inside a company network. When desktop SSO fails, users may be unable to activate Microsoft 365 Apps for enterprise or users may be prompted for forms-based logon even though they are using domain joined-computers from inside the company network.





Create your account and connect with a world of communities. Once I added the AlwaysUseMSOAuthForAutodiscover value, it popped up the modern auth prompt and worked perfectly. I’ve just switched on Modern Authentication in Office 365, following on from Microsoft’s recommendation.