when using a offline VisualStudio layout, you need to ensure the host you're downloading from is "trusted"

Add-TrustedHostDownloadSite.ps1

function Add-TrustedHostDownloadSite {
  [CmdletBinding()]
  param (
    [Parameter(Mandatory = $true)]
    [string]$ServerName,
    [Parameter(Mandatory = $false)]
    [string]$Domain = "myorg.somedomain"
    
  )
  Push-Location
  try {
    $zoneMapDomainsRegKeyPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains"
    Set-Location $zoneMapDomainsRegKeyPath
    New-Item $ServerName -ErrorAction SilentlyContinue
    Set-Location $ServerName
    New-ItemProperty . -Name file -Value 1 -Type DWORD  -ErrorAction SilentlyContinue
    Set-Location $zoneMapDomainsRegKeyPath
    New-Item $Domain  -ErrorAction SilentlyContinue
    Set-Location $Domain
    New-Item $ServerName  -ErrorAction SilentlyContinue
    Set-Location $ServerName
    New-ItemProperty . -Name file -Value 1 -Type DWORD  -ErrorAction SilentlyContinue	
  }
  finally {
    Pop-Location
  }
}