Microsoft Outlook Password Prompt Disappearing – Microsoft 365 Mailbox

One of the problems we are seeing quite often is Microsoft 365 email clients failing to connect to the Outlook servers which a message appearing with Password Required, but the box either appears and quickly disappears, or doesn’t accept any password put into it.

Wiping the profile and starting again doesn’t fix the issue either, so wasting the time of doing that (which can be a long and slow process if you have a large mailbox to download again) will greatly increase your downtime, when there is actually a quick solutions.

The issue is down to the way Outlook is authenticating with the servers, and is a particular issue with Outlook 2019 and Outlook 2021 which it looks like the systems is getting somewhat confused with Azure AD (when there is no Azure AD client).

A bit of background..

We have quite a diverse range of clients here at Midlands-IT.support, and with that diversity comes different investment in their IT systems.  Most of our customers use Microsoft Office Home and Business retail products, as they will use the software for the life of their device and then upgrade to the latest version when they get a new machine.

Almost all of our customers use Microsoft 365 for their email, as it a cost effective business email system with very little downtime and at £3.30 per mailbox per month represents good value, but the additional £6.80 per month to add Office / SharePoint and OneDrive which very few of them use means that they save around £350 buying Home and Business over the life of the device.

The fix…

Open Registry Editor and Navigate to HKEY_Current_User\Software\Microsoft\Office\16.0\Common\Identity

Right Mouse Click and select New – DWORD(32-bit Value)

Rename the new entry to DisableADALatopWAMOverride

Open the DisableADALatopWAMOverride key and change the value data to 1, click OK

Right Mouse Click and select New – DWORD(32-bit Value)

Rename the new entry to DisableAADWAM, open the key and change the value data to 1, click OK

Right Mouse Click and select New – DWORD(32-bit Value)

Rename the new entry to EnableADAL, open the key and change the value data to 1, click OK

Once you have created the 3 new DWORD keys, reboot the machine and after opening Outlook after reboot you should receive a password prompt which will then accept the password and connect.