I'm using Visual Studio 2015 community edition. But, suddenly all my ASP .Net 5 templates are missing. Any help would be highly appreciated
A new version of ASP.NET 5 was released a few weeks ago. It's now called ASP.NET Core and currently is at version RC2. So it doesn't use the ASP.NET 5 templates anymore. Under the Web templates you should have three selections:
ASP.NET Web Application (.NET Framework) - Used to create classic web applications.
ASP.NET Core Web Application (.NET Core) - Used to create pre-release ASP.NET Core applications that are cross-platform compatible.
ASP.NET Core Web Application (.NET Framework) - Used to create pre-release ASP.NET Core applications that are dependent on .NET Framework.
I installed Visual Studio Update 2 and ASP.NET Core RC2 one after the other. So I'm not sure which one changed the Web templates. But it seems that Update 2 did it since your ASP.NET 5 templates are gone and I assume you haven't installed ASP.NET Core RC2.
I would suggest upgrading to ASP.NET Core RC2 by following the install guide here. The ASP.NET 5 templates are gone for good. And there have been big changes with the latest release. Read about these changes here and here.