I had this exact issue on another machine, that after 2.5 hours on the phone with MS support (via Zoom), the solution was to uninstall MS Office 365 and reinstall it. Spent weeks with MS support and he got rather irritated when they told him to disable ADAL. He then started digging into Windows and how modern auth works and came across the above fix.
Office 365 won't log in without EnableADAL = 0
Check the version of Microsoft Office installed on your computer and your subscription name and expiry date. Office 365 applications installed on a computer must connect to Microsoft servers over the internet at least once every 30 days for the license to be checked and validated. If you don’t connect the installed Office 365 applications to Microsoft servers for more than 30 days in a row, these applications are deactivated. Once a connection is established to Microsoft licensing servers, the license is renewed.
Common Office 365 Issues and How to Solve Them
Use the NAKIVO solution to back up Microsoft 365 data in Exchange Online, Teams, OneDrive and SharePoint Online for uninterrupted workflows and zero downtime.
Fix authentication issues in Microsoft 365 apps when you try to connect to a Microsoft 365 service
If multiple versions of Microsoft Office are installed, Office 365 activation issues may occur. Uninstall old versions of Microsoft Office from your computer and try to activate Microsoft Office 365 again. This works for a week and then the issue raises it’s head again.
Information and fixes from Microsoft have been scant as well, outside of the registry key one.You can unintentionally send an important Microsoft 365 item to the recycle bin, especially if you have too many files on your device’s hard drive.I do NOT have this issue with the other laptop, an iPad, a MacBook Pro and tablet.I haven’t opened a ticket with MS yet but I may if my search does not prove fruitful.Safari can cause Microsoft 365 issues due to the Intelligent Tracking Prevention (ITP) feature.We have found on user endpoints that the AAD Broker Plugin is sometimes missing and this is what causes all manner of hell and headache with Microsoft applications/services for end users.You’d think after 10 years of O365 being used, the last thing you’d have issues with is Authentication… Yet here we are, same issue, different decade.This tool should be installed on a computer as a standalone application.And it’s random users, not all users experience this in this environment.
Microsoft 365 Issues Related to Updates
The good news is that the majority of problems can easily be solved on the client’s side. Microsoft recommends updating Windows, Microsoft Office and other software regularly. Microsoft updates are released on a regular basis and allow you to protect software against known threats, fix bugs, and so on. Office 365 known issues are usually fixed by these updates. Let’s find out what you can do if updates are not installed automatically, and what factors can cause update issues. Reboot your system and try to launch your Outlook app after to check if the synchronization issues are solved.
How to fix Office 365 login issue?
Step-by-Step Troubleshooting for Microsoft Office 365 Login IssuesCheck if the caps lock is on.Make sure you are using the correct account (work, school, or personal).Double-check the username and password before entering.Ensure there is no extra space before or after your username and password.
Additional resources
Many issues that you may face day-to-day can be fixed on the client side. If you encounter an issue in Office 365 that can only be fixed by the vendor, Microsoft usually releases an update to resolve any known issues as soon as possible. This is now the 2nd machine that presents the same issue. I have a valid MS 365 subscription that includes 5 device licenses. I checked my MS account info page, subscription is fine.
Try testing the configuration of your Office 365 email system and fix the problems that are preventing users from using the email services. Microsoft Support and Recovery Assistant can help you resolve problems with Microsoft Office, Office 365, and Outlook. Open the required file, hit Share and then check the list of users that you can give the rights to edit a file. You can set access permissions for the entire organization or invite only the users you specify. This error appears when you attempt to upload or save a Microsoft 365 item. It indicates that you have reached the storage limit specified by Step-by-step guide for Outlook stuck on profile your subscription plan.
You’d think after 10 years of O365 being used, the last thing you’d have issues with is Authentication… Yet here we are, same issue, different decade. If your Office 365 subscription has expired, buy a new license and extend your subscription for a new period. Or, any suggestion on how to fix this issue, even better.