Exchange Online PowerShell error - Cannot validate argument on parameter 'Session'

Question

We are a using an IAM tool that creates user accounts in Active Directory and then run a PowerShell script to enable their remote mailbox in exchange online.

Here is how the script looks like :

$so = New-PSSessionOption -SkipCNCheck

$ExchangeSession = New-PSSession -ConfigurationName Microsoft.Exchange -Credential $cred -ConnectionUri $msoExchangeURL -Authentication kerberos -SessionOption $so -Verbose

Import-PSSession $ExchangeSession -AllowClobber

Enable-RemoteMailbox -Identity $UPN

Remove-PSSession $ExchangeSession

The tool invokes the PowerShell script separately for each user that gets created on a day and these gets triggered parallelly, which means that multiple PowerShell sessions/exchange sessions gets opened parallelly. The script works perfectly fine when the user count is less, but when the count is large, say 50+, the PowerShell script starts throwing the below error for some of the users :

*Cannot validate argument on parameter 'Session'. The argument is null. Provide a valid value for the argument, and then try running the command again*

Has anyone faced a similar issue while dealing with multiple parallel exchange PowerShell sessions.? Any guidance would be much appreciated.

Answer 1

You cannot connect like this anymore since a while, legacy authentication is not supported.

You must download the latest ExchangeOnlineManagement module and use Connect-ExchangeOnline command.