Exchange Online Management v3.7.1 Authentication Error

If you're using Exchange Online Management PowerShell cmdlets, you may encounter the following error:

? A window handle must be configured. See https://aka.ms/msal-net-wam#parent-window-handles

This issue was introduced in version 3.7.0 (and persists in 3.7.1) due to Microsoft integrating Web Account Manager (WAM) into authentication flows for enhanced security.

?? Where does this happen?

? Works in a .NET console application

? Fails in PowerShell ISE and Windows-based applications like WinForms

?? Why does this happen?

Microsoft's MSAL library requires an interactive login prompt to have a parent window handle, ensuring the dialog isn’t hidden behind other windows. However, the implementation relies on GetConsoleWindow, which only works in console applications—causing failures in non-console environments.

? Workarounds

?? Option 1: Downgrade to v3.6.0

Uninstall-Module -Name ExchangeOnlineManagement -AllVersions -Force Install-Module -Name ExchangeOnlineManagement -RequiredVersion 3.6.0 -Force        

?? Option 2: Open a Console Window in PowerShell ISE (Not ideal, but works.)

$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()
}        

This issue persists in version 3.7.1, and there’s no official fix yet. Until then, these workarounds should help keep your workflows running smoothly.

?? Have you faced this issue? Let’s discuss in the comments! #ExchangeOnline #PowerShell #Microsoft365 #SysAdmin #Troubleshooting