The type or namespace name 'Optimization' does not exist in the namespace 'System.Web'

Question

I am deploying a new website as my main site and it works beautifully.

All of my applications under the root url work as well, except for one. It is a legacy system (c#

Answer 1

I faced same problem after create a new area in MVC5. There is auto generate web.config file. Check your web.config file under Views folder there is a line

1. if you need this then install it using following command.

   Install-Package Microsoft.AspNet.Web.Optimization
   

   at Package Manager Console like below

2. If you think no need then simply remove line from following section in web.config file