Richard Siddaway's Blog

A post on the PowerShell Team blog - https://blogs.msdn.microsoft.com/powershell/2016/02/24/windows-management-framework-wmf-5-0-rtm-packages-has-been-republished/ – reports that WMF 5.0 RTM has been republished.

You’ll have to uninstall the original RTM package before installing the new one.