PowerShell - The server committed a protocol violation

Let's understand what that error means and review 3 different ways to fix it.

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This sort article details a good trick for those getting the following error in PowerShell: 

The server committed a protocol violation

After googling ducking around, I found three different solutions for this problem:

1. Modifying your powershell.exe.config;
2. Modifying your request in order to avoid it stopping if your url is invalid in .NET
3. Modifying your request in order to avoid it stopping if your url is invalid in PowerShell.

Let's review each of them and understand a little more about the problem.

Solution 1 - Modifying powershell.exe.config

This solution will apply to all PowerShell requests so use with caution. Also, this solution is not portable so, if you plan to run this script on a machine you don't have admin access to, this solution will probably not work.

<system.net>

<settings>

<httpWebRequest useUnsafeHeaderParsing="true" />

</settings>

</system.net>

Solution 2 - Modifying your request in .NET

To modify your request, have the code below before you actually run Invoke-WebRequest:

$netAssembly = [Reflection.Assembly]::GetAssembly([System.Net.Configuration.SettingsSection])

if($netAssembly)
{
    $bindingFlags = [Reflection.BindingFlags] "Static,GetProperty,NonPublic"
    $settingsType = $netAssembly.GetType("System.Net.Configuration.SettingsSectionInternal")

    $instance = $settingsType.InvokeMember("Section", $bindingFlags, $null, $null, @())

    if($instance)
    {
        $bindingFlags = "NonPublic","Instance"
        $useUnsafeHeaderParsingField = $settingsType.GetField("useUnsafeHeaderParsing", $bindingFlags)

        if($useUnsafeHeaderParsingField)
        {
          $useUnsafeHeaderParsingField.SetValue($instance, $true)
        }
    }
}

Solution 3 - Modifying your request in PowerShell

This is probably the simplest. Just run the line below:

[System.Net.ServicePointManager]::ServerCertificateValidationCallback = { $true }

Conclusion

On this post we reviewed three different ways to resolve a problem in PowerShell. Don't know PowerShell yet? I would urge you to take a look and learn it (even if just the basics). PowerShell is a powerful tool used extensively in devops on Windows, Azure and Linux.

References

• Invoke-WebRequest
• Ignoring SSL trust in PowerShell System.Net.WebClient
• Invoke-WebRequest - protocol violation when attempting to login using XML

See Also

• My journey to 1 million articles read
• Getting last modified software on Windows using PowerShell
• Determining installed .NET Framework versions using PowerShell
• Windows Subsystem for Linux, the best way to learn Linux on Windows
• Why I use Fedora Linux
• How I fell in love with i3
• Diagnosing and Fixing WSL initialization issues
• Creating a Ubuntu Desktop instance on Azure
• Hosting NuGet packages on GitHub
• My journey to 1 million articles read
• How and why use stronger passwords