I am sure that, some of you, who read me, you will be presented with a very annoying error when configuring/accessing Outlook 2016/2019 in its desktop version. The error I am talking about is the one that no matter how much they place the password of the account well, the window still appears requesting the user’s credentials. An image similar to the following:

 

 

The Outlook Desktop connection settings for this specific case were Microsoft Exchange. There were no problems with DNS settings or with Autodiscover, Outlook was up to date, and there were no problems with the Office 365 account at any level. So where was the problem? 

Well, after researching it was detected that in the Office 365 Tenant, modern authentication for Exchange Online was disabled. To activate modern authentication, we must execute a series of PowerShell commands, which I mention below: 

1.- Run PowerShell as administrator 

2.- Use TLS 1.2 on the PowerShell connection 

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]:::Tls12 

3.- Configure script execution policy in Powershell 

Set-ExecutionPolicy Unrestricted -Force 

4.- Install the following modules 

Install-Module PowershellGet -Force 

Install-Module ExchangeOnlineManagement -Force 

5.- Connect to the Exchange Online module 

Connect-ExchangeOnline 

6.- View the current value of Modern Authentication for Exchange Online 

Get-OrganizationConfig | Select OAuth2ClientProfileEnabled 

If the value of OAuth2ClientProfileEnabled is set to False, you must run the cmdlet in step 7. 

7.- Enable modern authentication for Exchange Online  

Set-OrganizationConfig -OAuth2ClientProfileEnabled $true 

Now, we’ve enabled modern authentication for Exchange Online. The connection problems that were presented at the time of accessing/configuring Outlook disappeared once activated. 

For a little more information about the process, I invite you to review the following official documentation: 

Enable or disable modern authentication for Outlook in Exchange Online | Microsoft Docs 

Introduction to modern hybrid authentication and prerequisites for use with on-premises Skype for Business and Exchange servers – Microsoft 365 Enterprise | Microsoft Docs 

I say goodbye and hope that this article will help you and be part of your knowledge library.