Exchange Online Management v3.7.1 Authentication Error

Users leveraging Exchange Online Management PowerShell cmdlets may encounter the following error message: "❌ A window handle must be configured. See https://aka.ms/msal-net-wam#parent-window-handles".

This error was introduced in version 3.7.0 and remains present in version 3.7.1. The root cause is attributed to the integration of Microsoft's Web Account Manager (WAM) into authentication flows, a change intended to bolster security.

The behavior observed is inconsistent across different environments:

  • It functions as expected within .NET console applications.
  • It fails when used in PowerShell ISE and other Windows-based applications such as WinForms.

The technical explanation involves the Microsoft Authentication Library (MSAL) requiring a parent window handle for interactive login prompts. This requirement ensures the authentication dialog is not obscured by other windows. However, the current implementation relies on the GetConsoleWindow function, which is exclusively effective in console environments, leading to the observed failures in non-console applications.

As of now, an official resolution for this issue in versions 3.7.0 and 3.7.1 has not been released. In the interim, the following workarounds can be employed:

  • Downgrading the Module: Reverting to version 3.6.0 is a viable option.
    Uninstall-Module -Name ExchangeOnlineManagement -AllVersions -Force
    Install-Module -Name ExchangeOnlineManagement -RequiredVersion 3.6.0 -Force
    
  • Creating a Console Window (Specific to PowerShell ISE): While not an optimal long-term solution, this code snippet can temporarily address the issue:
    $ConsoleHelper = @'
    using System;
    using System.Runtime.InteropServices;
    public class ConsoleHelper {
       [DllImport("kernel32.dll")] public static extern int AllocConsole();
       [DllImport("kernel32.dll")] public static extern int FreeConsole();
    }
    '@
    
    Add-Type -TypeDefinition $ConsoleHelper
    
    try {
       [ConsoleHelper]::AllocConsole()
       Connect-ExchangeOnline
    } finally {
       [ConsoleHelper]::FreeConsole()
    } 

These temporary solutions should facilitate continued operation of your workflows pending an official fix. 

Comments

Popular posts from this blog

PowerShell Basics for Office 365 Administration (Episode 3)

PowerShell Basics for Office 365 Administration (Episode 4): Conditional Logic and Looping Structures

Unveiling Primary Mailbox Statistics