PowerShell Installing NuGet, says unable to access internet, but I actually can

Question

I followed the steps mentioned in Using PowerShell Behind a Proxy to configure my proxy server.

netsh winhttp set proxy \"[IP]:[Port]\"
$Wcl = New-Object System.         


        

Answer 1

As per https://community.spiceworks.com/topic/2265662-powershell-get-download-problem

I had the same problem today...

My issue was PowerShell Gallery would not download anything on W2016 boxes:

VERBOSE: InstallPackage' - name='AzureRM.BootStrapper',
version='0.5.0',destination='C:\Users\Administrator\AppData\Local\Temp\2\1254134668'
VERBOSE: DownloadPackage' - name='AzureRM.BootStrapper',
version='0.5.0',destination='C:\Users\Administrator\AppData\Local\Temp\2\1254134668\AzureRM.BootStrapper\AzureRM.BootSt
rapper.nupkg', uri='https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0'
VERBOSE: Downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0'.
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '2' more
times
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '1' more
times
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '0' more
times
VERBOSE: Downloading package 'AzureRM.BootStrapper' failed, please make sure
'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' is accessable.
WARNING: Source Location 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' is not valid.
PackageManagement\Install-Package : Package 'AzureRM.BootStrapper' failed to download.
At C:\Program Files\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\PSModule.psm1:1772 char:21
+ ...          $null = PackageManagement\Install-Package @PSBoundParameters
+                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ResourceUnavailable: (C:\Users\Admini...tStrapper.nupkg:String) [Install-Package], Excep
   tion
    + FullyQualifiedErrorId : PackageFailedInstallOrDownload,Microsoft.PowerShell.PackageManagement.Cmdlets.InstallPac
   kage

What helped me to find out it was TLS v1.2 was this error in Fiddler:

System.Security.Authentication.AuthenticationException A call to SSPI failed, see inner exception

From there I got this -> A call to SSPI failed, see inner exception - The Local Security Authority cannot be contacted

Then tested locally with:

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

Which worked fine!

Hopefully, that will help somebody in the future :-)

You can set it for the whole .NET framework by editing registry:

# Set strong cryptography on 64 bit .Net Framework (version 4 and above)
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord


# Set strong cryptography on 32 bit .Net Framework (version 4 and above)
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord 

This happened a few days ago on Windows Server 2016 Datacentre boxes, Win 2019 works fine still.

Commands thanks to: https://johnlouros.com/blog/enabling-strong-cryptography-for-all-dot-net-applications

Happy Azure Stacking!!!