On August 23, Windows update KB3176934 released for Windows Client. Due to a missing .MOF file in the build package, the update breaks DSC. All DSC operations will result in an “Invalid Property” error.

In addition, due to a missing binary in the build package, the update breaks PowerShell Implicit Remoting. Implicit remoting is a PowerShell feature where PowerShell commands work on a remote session instead of locally. Specifically, importing a remote session no longer works:

$remoteSession = New-PSSession -Cn TargetComputer
Import-PSSession -Session $remoteSession

Import-PSSession : Could not load type ‘System.Management.Automation.SecuritySupport’ from assembly
‘System.Management.Automation, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35’.

To prevent these issues take the following actions:

1. If you are using DSC from or on any Windows client, take the following steps:
   Uninstall the update if already installed. From elevated PowerShell prompt type

   wusa /uninstall /kb:3176934

2. If using WSUS, do not approve the update. Otherwise, Use Group Policy to set the ‘Configure Automatic Updates’ to ‘2 – Notify for download and notify for install’ as described in this Microsoft Support article.

According to Microsoft, a fix for this issue will be included in the next Windows update which is due out 8/30/2016.