GUI-Script funktioniert nur in ISE aber nicht als PS-Aufruf oder .exe

%windir%\System32\WindowsPowerShell\v1.0\powershell.exe -NoLogo -NonInteractive -File "C:\temp\GUI_im_Hintergund_Test\GUI_im_Hintergund_Test.ps1"  

$global:synkTable = [System.Collections.Hashtable]::Synchronized(@{})

Add-Type -AssemblyName system.windows.forms;
[void][reflection.assembly]::Load('System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089')  
[void][reflection.assembly]::Load('System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a')  

$global:synkTable = [System.Collections.Hashtable]::Synchronized(@{})
$GUI_im_Hintergund_Test_FormClosing ={}
$button_leeren_Click = {}

if ($synkTable.iRS_GEN_Status -eq $null -or $synkTable.iRS_GEN_Status -in 'Completed', 'Failed', 'Stopped') {  
    .(Join-Path $PSScriptRoot 'GUI_im_Hintergund_Test.designer.ps1')   
    $RS_GEN = [System.Management.Automation.Runspaces.RunspaceFactory]::CreateRunspace()
    $RS_GEN.Name = "RS_GEN";   
    $RS_GEN.ApartmentState = "STA";   
    $RS_GEN.ThreadOptions = "ReuseThread"   
    $RS_GEN.Open(); 
    $RS_GEN.SessionStateProxy.SetVariable('synkTable',$global:synkTable)  
    $synkTable.GUI_im_Hintergund_Test = $GUI_im_Hintergund_Test
    $iRS_GEN = [powershell]::Create().addScript({
    [System.Windows.Forms.Application]::Run($synkTable.GUI_im_Hintergund_Test)
    # $synkTable.GUI_im_Hintergund_Test.ShowDialog() # Funktioniert aber dennoch exception nach GUI Interaktion
    })
    $iRS_GEN.Runspace.Name = "iRS_GEN"; $iRS_GEN.Runspace = $RS_GEN  
    Register-ObjectEvent -InputObject $iRS_GEN -EventName InvocationStateChanged -SourceIdentifier "iRS_GEN_InvocationStateInfo" -Action {  
        $iRS_GEN_Status = $Event.SourceEventArgs.InvocationStateInfo.State
        $synkTable.iRS_GEN_Status = $iRS_GEN_Status
        if ($iRS_GEN_Status -in 'Completed', 'Failed', 'Stopped') {  
                $iRS_GEN.Runspace.Close(); 
                $RS_GEN.Dispose()
                Unregister-Event -SourceIdentifier $($Event.SourceIdentifier) 
                Remove-Job -Name $($Event.SourceIdentifier) 
        }} ; $iRS_GEN.BeginInvoke()}

[void][System.Reflection.Assembly]::Load('System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a')  
[void][System.Reflection.Assembly]::Load('System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089')  
$GUI_im_Hintergund_Test = New-Object -TypeName System.Windows.Forms.Form
[System.Windows.Forms.Button]$button_leeren = $null
[System.Windows.Forms.FolderBrowserDialog]$folderBrowserDialog_ScannPath = $null
[System.Windows.Forms.TextBox]$textBox1 = $null
[System.Windows.Forms.Button]$button1 = $null
function InitializeComponent
{
$resources = . (Join-Path $PSScriptRoot 'GUI_im_Hintergund_Test.resources.ps1')  
$button_leeren = (New-Object -TypeName System.Windows.Forms.Button)
$folderBrowserDialog_ScannPath = (New-Object -TypeName System.Windows.Forms.FolderBrowserDialog)
$textBox1 = (New-Object -TypeName System.Windows.Forms.TextBox)
$GUI_im_Hintergund_Test.SuspendLayout()
#
#button_leeren
#
$button_leeren.Anchor = ([System.Windows.Forms.AnchorStyles][System.Windows.Forms.AnchorStyles]::Top -bor [System.Windows.Forms.AnchorStyles]::Right)
$button_leeren.Location = (New-Object -TypeName System.Drawing.Point -ArgumentList @([System.Int32]641,[System.Int32]13))
$button_leeren.Name = [System.String]'button_leeren'  
$button_leeren.Size = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]131,[System.Int32]30))
$button_leeren.TabIndex = [System.Int32]1
$button_leeren.Text = [System.String]'Leeren'  
$button_leeren.UseVisualStyleBackColor = $true
$button_leeren.add_Click($button_leeren_Click)
#
#folderBrowserDialog_ScannPath
#
$folderBrowserDialog_ScannPath.add_HelpRequest($folderBrowserDialog_ScannPath_HelpRequest)
#
#textBox1
#
$textBox1.Location = (New-Object -TypeName System.Drawing.Point -ArgumentList @([System.Int32]12,[System.Int32]47))
$textBox1.Multiline = $true
$textBox1.Name = [System.String]'textBox1'  
$textBox1.Size = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]760,[System.Int32]452))
$textBox1.TabIndex = [System.Int32]2
#
#GUI_im_Hintergund_Test
#
$GUI_im_Hintergund_Test.AutoScroll = $true
$GUI_im_Hintergund_Test.ClientSize = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]784,[System.Int32]511))
$GUI_im_Hintergund_Test.Controls.Add($textBox1)
$GUI_im_Hintergund_Test.Controls.Add($button_leeren)
$GUI_im_Hintergund_Test.Icon = ([System.Drawing.Icon]$resources.'$this.Icon')  
$GUI_im_Hintergund_Test.MinimumSize = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]800,[System.Int32]550))
$GUI_im_Hintergund_Test.Name = [System.String]'GUI_im_Hintergund_Test'  
$GUI_im_Hintergund_Test.Text = [System.String]'Test'  
$GUI_im_Hintergund_Test.TopMost = $true
$GUI_im_Hintergund_Test.ResumeLayout($false)
$GUI_im_Hintergund_Test.PerformLayout()
Add-Member -InputObject $GUI_im_Hintergund_Test -Name button_leeren -Value $button_leeren -MemberType NoteProperty
Add-Member -InputObject $GUI_im_Hintergund_Test -Name folderBrowserDialog_ScannPath -Value $folderBrowserDialog_ScannPath -MemberType NoteProperty
Add-Member -InputObject $GUI_im_Hintergund_Test -Name textBox1 -Value $textBox1 -MemberType NoteProperty
Add-Member -InputObject $GUI_im_Hintergund_Test -Name button1 -Value $button1 -MemberType NoteProperty
}
. InitializeComponent