Remote Invoke-Command Powershell Stop-WebAppPool No Longer Working After Powershell 5 Upgrade
The full details of the issue are already documented on Server Fault here: http://serverfault.com/questions/806794/remote-invoke-command-powershell-stop-webapppool-no-longer-working-after-powersh
The gist of it is that we have Server A which was on WMF 4 / PowerShell 4 and was able to issue Invoke-Command calls to Server B which was on WMF 2 / PowerShell 2. In particular, a call to Stop-WebAppPool. After upgrading Server A to WMF 5, the call to Stop-WebAppPool no longer works. However, issuing this command to other Servers on WMF 4/5 seems to work.
Jake Gordon commented
Upgrading the "Server B" to WMF 4 solved the problem. Still not sure why it doesn't work when connecting to a machine with PowerShell 2.