Powershell types

$path = "D:\TEST"

$signature = @'
[DllImport("msi.dll", CharSet=CharSet.Unicode)]
public static extern unsafe int MsiGetProperty(
    int hInstall,
    string szName,
   [Out] StringBuilder szValueBuf,
   ref int pchValueBuf);

[DllImport("msi.dll", CharSet = CharSet.Unicode, PreserveSig = true, SetLastError = true, ExactSpelling = true)]
public static extern unsafe UInt32 MsiOpenPackageEx(
     string szPackagePath,
     UInt32 dwOptions,
     [Out] void **hProduct);
'@
$unsafe = New-Object System.CodeDom.Compiler.CompilerParameters
$unsafe.CompilerOptions="/unsafe"

[int] $code
[IntPtr]$ptr = [IntPtr]::zero
[string] $property = "ProductCode"

$output = New-Object System.Text.StringBuilder(512);

Add-Type -MemberDefinition $signature -Name ProductCodeCustom -Namespace CustomScript -PassThru -Using System.Text -CompilerParameters $unsafe
[CustomScript.ProductCodeCustom]::MsiOpenPackageEx($path, 1, [ref] $ptr)
[CustomScript.ProductCodeCustom]::MsiGetProperty([ref] $code, $property, $null, $output.MaxCapacity)

$output.ToString()

////////////////ERRRRRRRRRRORRRRRRRRRRR CCCCCOOOOOOODDDDDDDEEEEEEESSSS//////////////////////

Exception calling "MsiOpenPackageEx" with "3" argument(s): "Operation could destabilize the runtime."
+ [CustomScript.ProductCodeCustom]::MsiOpenPackageEx($path, 1, [ref] $p ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : VerificationException

[ref] cannot be applied to a variable that does not exist.
+ [CustomScript.ProductCodeCustom]::MsiGetProperty([ref] $code, $proper ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (code:VariablePath) [], RuntimeException
    + FullyQualifiedErrorId : NonExistingVariableReference