Cannot call show dialog() on a null-valued expression - powershell

Question

I am trying to open the next page of my Winforms script and atm on first launch the error is get when clicking the next button is "you cannot call a method on a null-valued expression" [void] $Form_UserInformation.ShowDialog() being the issue code here. When I run it the second time it runs fine but this doesn't work for an EXE file as it closes it and doesn't remember the previous session.
# HomePage Form
$Form_HomePage = New-Object System.Windows.Forms.Form
$Form_HomePage.text = "New User Script"
$Form_HomePage.Size = New-Object System.Drawing.Size(400,400)
$Form_HomePage.FormBorderStyle = "FixedDialog"
$Form_HomePage.TopMost = $false
$Form_HomePage.MaximizeBox = $false
$Form_HomePage.MinimizeBox = $true
$Form_HomePage.ControlBox = "true"
$Form_HomePage.StartPosition = "CenterScreen"
$Form_HomePage.Font = "Segoe UI"
# Title label
$label_HomeTitle = New-Object System.Windows.Forms.Label
$label_HomeTitle.Location = New-Object System.Drawing.Size(47,8)
$label_HomeTitle.Size = New-Object System.Drawing.Size(300,42)
$label_HomeTitle.Font = New-Object System.Drawing.Font("Segoe UI",24,[System.Drawing.FontStyle]::Regular)
$label_HomeTitle.TextAlign = "MiddleCenter"
$label_HomeTitle.Text = "Kuehne && Nagel"
$Form_HomePage.Controls.Add($label_HomeTitle)
# Subheading label
$label_HomeSubTitle = New-Object System.Windows.Forms.Label
$label_HomeSubTitle.Location = New-Object System.Drawing.Size(50,60)
$label_HomeSubTitle.Size = New-Object System.Drawing.Size(300,42)
$label_HomeSubTitle.Font = New-Object System.Drawing.Font("Segoe UI",16,[System.Drawing.FontStyle]::Regular)
$label_HomeSubTitle.TextAlign = "MiddleCenter"
$label_HomeSubTitle.Text = "New User Script"
$Form_HomePage.Controls.Add($label_HomeSubTitle)
# Next button
$button_HomeStart = New-Object System.Windows.Forms.Button
$button_HomeStart.Location = New-Object System.Drawing.Size(75,200)
$button_HomeStart.Size = New-Object System.Drawing.Size(240,32)
$button_HomeStart.TextAlign = "MiddleCenter"
$button_HomeStart.Text = "Start"
$button_HomeStart.Add_Click({
[void] $Form_UserInformation.ShowDialog()
$Form_HomePage.Hide()
})
$Form_HomePage.Controls.Add($button_HomeStart)
# About button
$button_About = New-Object System.Windows.Forms.Button
$button_About.Location = New-Object System.Drawing.Size(75,250)
$button_About.Size = New-Object System.Drawing.Size(240,32)
$button_About.TextAlign = "MiddleCenter"
$button_About.Text = "About"
$button_About.Add_Click({
})
$Form_HomePage.Controls.Add($button_About)
# Exit button
$button_HomeExit = New-Object System.Windows.Forms.Button
$button_HomeExit.Location = New-Object System.Drawing.Size(75,300)
$button_HomeExit.Size = New-Object System.Drawing.Size(240,32)
$button_HomeExit.TextAlign = "MiddleCenter"
$button_HomeExit.Text = "Exit"
$button_HomeExit.Add_Click({
$Form_HomePage.Close()
})
$Form_HomePage.Controls.Add($button_HomeExit)
# Show Form
$Form_HomePage.Add_Shown({$Form_HomePage.Activate()})
[void] $Form_HomePage.ShowDialog()
# User Information Form
$Form_UserInformation = New-Object System.Windows.Forms.Form
$Form_UserInformation.text = "New User Script"
$Form_UserInformation.Size = New-Object System.Drawing.Size(400,400)
$Form_UserInformation.FormBorderStyle = "FixedDialog"
$Form_UserInformation.TopMost = $false
$Form_UserInformation.MaximizeBox = $false
$Form_UserInformation.MinimizeBox = $true
$Form_UserInformation.ControlBox = "true"
$Form_UserInformation.StartPosition = "CenterScreen"
$Form_UserInformation.Font = "Segoe UI"