Script works in ISE and not SOME powershell CLI - powershell

Question

$wshell = New-Object -ComObject Wscript.Shell
$wshell.Popup("********Please Select the SOURCE Directory********",0,"Directory Selecter 5000",0x1)
Function Get-Folder($initialDirectory)
{
$foldername = New-Object System.Windows.Forms.FolderBrowserDialog
$foldername.rootfolder = "MyComputer"
if($foldername.ShowDialog() -eq "OK")
{
$folder += $foldername.SelectedPath
}
return $folder
}
$a = Get-Folder
$wshellb = New-Object -ComObject Wscript.Shell
$wshellb.Popup("********Please Select the DESTINATION Directory********",0,"Directory Selecter 5000",0x1)
Function Get-Folder($initialDirectory)
{
$foldername = New-Object System.Windows.Forms.FolderBrowserDialog
$foldername.rootfolder = "MyComputer"
if($foldername.ShowDialog() -eq "OK")
{
$folder += $foldername.SelectedPath
}
return $folder
}
$b = Get-Folder
Set-Content -Path "C:\script\scripts\script data.txt" -Value "$a" -Force
Set-Content -Path "C:\script\scripts\script data2.txt" -Value "$b" -Force
So this script works in ISE and if I copy/paste it into a CLI and that's it. If I navigate to the folder in the powershell CLI and run it from there it gives me this error:
New-Object : Cannot find type
[System.Windows.Forms.FolderBrowserDialog]: verify that the assembly
containing this type is loaded. At
C:\script\scripts\pathingworking.ps1:8 char:19
+ $foldername = New-Object System.Windows.Forms.FolderBrowserDialog
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidType: (:) [New-Object], PSArgumentException
+ FullyQualifiedErrorId : TypeNotFound,Microsoft.PowerShell.Commands.NewObjectCommand
The property 'rootfolder' cannot be found on this object. Verify that
the property exists and can be set. At
C:\script\scripts\pathingworking.ps1:9 char:5
+ $foldername.rootfolder = "MyComputer"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : PropertyNotFound
You cannot call a method on a null-valued expression. At
C:\script\scripts\pathingworking.ps1:11 char:8
+ if($foldername.ShowDialog() -eq "OK")
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
This error comes back twice, once for each instance of the folder selection window that is supposed to pop up.
I have tried -STA from run dialogue, shortcuts, and even from the CLI and it always gives me that error. I have verified using [System.Threading.Thread]::CurrentThread.GetApartmentState() that the open instance of powershell is STA. I can open a powershell CLI and navigate to the folder where the script is, invoke the script, it will give me the error, then I can copy\paste it in the same exact CLI and it works without issue. I have also right-clicked the file in Explorer and selected "run with powershell" and it also gives me the error. I have elevated the CLI to see if that helped with no success.
I fear this is some small oversight and hopefully someone can give me a hand.
using v1.0
windows 10

Answer 1

Cannot find type [System.Windows.Forms.FolderBrowserDialog] is due to the assembly not being loaded.
load the assembly with
Add-Type -AssemblyName "System.Windows.Forms"

Answer 2

rerun's answer solves the errors, but doesn't do a whole lot of explaining. Designing a script in the ISE (which is what I do almost exclusively) is convenient because it will automatically load types and modules for you. If you plan on running the script from another CLI (Command Line Interpreter) you should make it a habit of explicitly loading needed modules and assemblies early on in the script, so that when those things are called upon later PowerShell will know what you're asking for.
Unfortunately there's no easy way to tell what you will need to do that for when it comes to what types are going to be inherently available, but a little trial and error usually points it out rather quickly, or if you look at your script and see that you are making a new object with System.Kitchen.Pasta, then you probably need to load the assembly for System.Kitchen first, so that it has the Pasta type available when you want it, so you could just include a call to load that assembly near the top of the script with no harm done.
In your specific case, as has already been pointed out, you will need to load the assembly that contains the FolderBrowserDialog box that you want to display. Adding the following as the first line of your script will resolve the errors that you are seeing:
Add-Type -AssemblyName "System.Windows.Forms"