Fix Password Prompt for MS Office Activation Disappears When MFA is Turned ON

Try to open Outlook in safe mode

Open Run (Windows + R) and type Outlook.exe /safe and click Enter. open Outlook in safe mode

Choose the profile that you want to open. If the dialog box appears for the password, then input it and start the application.

Validate the account using MS Word

If the issue persists in Outlook, you can close it and validate that account using other MS Office applications like MS Word, Excel, PowerPoint, etc.

Close Outlook and open a blank MS Word document.

Click File and go to the Account section. Click Sign out and close the documents. Close Outlook and open a blank MS Word

Open Outlook again and input account credentials to verify the account.

Clear Credentials Manager

You can clear the existing credentials for your whole MS Office Suite and help the application to register again.

Open Credentials Manager and click on the Windows Credentials option. Clear Credentials Manager

Click the Remove option to delete the credentials of MS Office Suite. Remove delete the credentials of MS Office Suitev

Restart Outlook and input the new credentials.

Create a DWORD registry with value 1

Open regedit (Registry Editor) and go to the following location-

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity

Create a new DWORD with the name – EnableADAL with a value 0.
NOTE – ADAL will enable the sign-in capability for multi-factor authentication in MS Office apps.

In the same location, create another DWORD key with DisableADALatopWAMOverride and set the value to 1.

Restart the computer as it will help the registries to start working.

The new value will disable the Web Account Manager and disable the multi-factor authentication.

Reinstall the MS Office apps

You can uninstall all the existing MS Office 365 apps and download them again. There is an option to Install Office 365 APIs. You can click it, and the download will start.

After installing the application, you can add accounts again. It may remove the problem of constant password dialog box disappearance.

Repair the Outlook profile

A reason behind and constant occurrence/disappearance of the password dialog box may be a bad database file that has lost connection with the online account. When you have enabled multi-factor authentication, you should reattach the account in Outlook or repair the data file. You can use the Inbox Repair tool to scan it and repair the data file.

Conclusion

Multi-factor authentication increases the security of the Office 365 account and requires the user to provide additional information like a code through an SMS or phone call. But, sometimes, you may get error messages, which you can fix easily. You can also disable multi-factor authentication, but it puts the account at more security risks. But if you are facing Outlook PST corruption issues, you can use Kernel Outlook PST Repair software that scans the data file and recovers the entire account. Kernel PST Repair shows the recovered items in a preview pane, and later you can save them in an Office 365 mailbox.