powershell proxy openssh windows-server-2019

How can I utilize the Add-WindowsCapability function through a proxy in PowerShell?

I am trying to install OpenSSH on a Windows Server 2019 machine in an environment without external network access and with a configured proxy at "http://10.99.99.99:80". I am using PowerShell with administrative privileges and have set the HTTP_PROXY and HTTPS_PROXY environment variables as follows:

$Proxy = "http://10.99.99.99:80"
$ENV:HTTP_PROXY=$proxy
$ENV:HTTPS_PROXY=$proxy

However, when I try to install OpenSSH using the following command:

Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0

I receive the following error:

Add-WindowsCapability : Add-WindowsCapability failed. Error code = 0x800f0954 At line:1 char:1 + Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0 + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Add-WindowsCapability], COMException + FullyQualifiedErrorId : Microsoft.Dism.Commands.AddWindowsCapabilityCommand

Other Invoke-WebRequests I am making seem to have proxy access, but the Add-WindowsCapability command is not working. I am unable to resolve this issue.

Solution

The message has error code 0x800f0954, you may want try doing the following steps:

Open gpedit.msc
Navigate to Computer Configuration -> Administrative Templates -> System
Double click on Specify settings for optional component installation and component repair to open its settings
Check "Enabled" in the popup dialog
Check Download repair content and optional features directly from Windows Updates instead of Windows Server Updates Services (WSUS)
Open Powershell, Run gpupdate /force
Rerun the Add-WindowsCapability again, it should be fixed