I just encountered something I thought was odd - Visual Studio 2015 Enterprise was complaining when trying to create a new C# unit test project. It might be because I'm on Windows 10, I don't know - I only run Windows 10 for development now.
The error was :
Error: Could not load file or assembly Microsoft.VisualStudio.JSLS Version=18.104.22.168
- Mount the VS 2015 ISO
- Restart Visual Studio