[Fixed] ASP.NET 4.5 has not been registered on the Web server.
After the installation of the Microsoft .NET Framework 4.6, users may experience the following dialog box displayed in Microsoft Visual Studio when either creating new Web Site or Windows Azure project or when opening existing projects.
Configuring Web http://localhost:64886/ for ASP.NET 4.5 failed. You must manually configure this site for ASP.NET 4.5 in order for the site to run correctly. ASP.NET 4.0 has not been registered on the Web server. You need to manually configure your Web server for ASP.NET 4.0 in order for your site to run correctly.
Microsoft has published a fix for all impacted versions of Microsoft Visual Studio.