Cannot open Web projects in Visual Studio 2013

This happens due to corrupt applicationHost.config file.

Instead of re-installing visual studio,

Go to C:\inetpub\history and copy applicationHost.config file to My Documents\IISExpress\config\

This should solve your problem.

I had the similar occurrence for a specific project only for VS 2015.

I went to the respective project folder .vs\config drive and deleted the applicationhost.config file. Then reloaded the project, and it created a new application host file and reloaded successfully.