"The requested content appears to be script and will not be served by the static file handler" error message on IIS 8.5/Windows Server 2012 R2

I was recently installing Sourcegear Vault on my Windows Server 2012 R2 server when I received the following error message:

Well, based on past experience, I figured that I would have to run the aspnetregiis -i command at the command prompt in order to get the ASP.NET Script Mappings appropriately configured.

Well, much to my surprise, I encountered the following error message:

Therefore, I could no longer use this tried and tested command to register ASP.NET 4.0/4.5 in IIS!  I would have to do it manually through Add/Remove Windows Features!!

Well, fortunately, I had Microsoft Web Platform Installer installed on my computer, so I simply used that to install and configure ASP.NET 4.5 for me!

After doing that, my ASP.NET Web Applications were working just fine!