I installed the Pro version of Visual Studio 2015 in Windows 10 for testing.
When creating a project should open a screen with the options as in the image below:
Butitopenslikethis:
DoesnotshowASP.NET5Templatesoptions.
ItriedtoaddbyTools->Extensionstonoavail.
IusedtheRepairoptionandnothingtoo.Includingthe"Web Developer Tools" option checked.
I saw some posts that only solved the problem by formatting the machine.