I was polishing off a deployment script today and wanted to check my syntax for Comment Based Help. Now not remembering the exact name of the about_ help topic I ran the following to get the full list.
To my surprise the usually long list of help topics was quite short. It turns out this is a bug introduced in WMF 5.0. More information about this issue can be found at the PowerShell GitHub repository.
I’m certain the issue will be fixed in good time, in the meantime head over the the PowerShell Gallery and run the Install-AboutHelp script to fix the issue.