Powershell Set-ADAccountPassword : Zugriff Verweigert

                $Name=$InputBoxUser.text;
                $User=Get-ADUser -Filter "Name -eq '$Name'" -Properties SamAccountName   
				$Password = ''  
 				$random = New-Object System.Random
				1..10 | ForEach { $Password = $Password + [char] $random.next(48,123) }
				$SetPassword = ConvertTo-SecureString -AsPlainText $Password -Force
                $outputbox.Text +="`r`n"  
                $OUGUID
                $outputbox.Text += Invoke-Command @ServerSettings -Credential $cred -ArgumentList ($User,$SetPassword,$OUGUID) -ScriptBlock{
                Param($user,$SetPassword,$TargetOU)
                $ou=$TargetOU.Item("TargetPath")  
                ("User deaktiviert: "+$user.SamAccountName)   
                Get-AdUser -Identity $user.SamAccountName | Set-ADAccountPassword -NewPassword $SetPassword -Reset -Confirm:$false
                Get-AdUser -Identity $user.SamAccountName | Set-ADAccountControl -CannotChangePassword:$true
                Get-ADPrincipalGroupMembership -Identity $user.SamAccountName | % {Remove-ADPrincipalGroupMembership -Identity $user.SamAccountName -MemberOf $_ -Confirm:$false}
                Get-AdUser -Identity $user.SamAccountName | Move-ADObject -TargetPath $ou
                Get-AdUser -Identity $user.SamAccountName | Disable-ADAccount
                } -ErrorAction SilentlyContinue -ErrorVariable ErrDelUser -WarningVariable WarningDelUser

Set-ADAccountPassword : Zugriff verweigert
In Zeile:1 Zeichen:45
+ Get-AdUser -Identity $user.SamAccountName | Set-ADAccountPassword -NewPassword $ ...
+                                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : PermissionDenied: (CN=USER...DC=domain,DC=local:ADUser) [Set-ADAccountPassword], Un
   authorizedAccessException
    + FullyQualifiedErrorId : ActiveDirectoryCmdlet:System.UnauthorizedAccessException,Microsoft.ActiveDirectory.Manag
   ement.Commands.SetADAccountPassword