Creating an ASP.NET Core MVC Web project in Visual Studio 2017 , I found that in the _Layout.cshtml a has an attribute called asp-area but it has no value:
<li><a asp-area="" asp-controller="Home" asp-action="Index">Home</a></li>
<li><a asp-area="" asp-controller="Home" asp-action="About">About</a></li>
<li><a asp-area="" asp-controller="Home" asp-action="Contact">Contact</a></li>
After all, what is the purpose of this attribute?
Basically to inform you that a link / route refers to an area
ASP.NET Core areas
As ASP.NET will look for a controller in the Controllers folder in the root of the site, if you want to use a controller that is in a specific area needs to report using the asp-area attribute.
Example:
/
/Areas
/Admin
/Controllers
/UsuarioController.cs
/Controllers
/LoginController.cs
To link to the controller at the root, just use asp-area=""
<a asp-area="" asp-controller="Login" asp-action="Index">Logar</a>
For the controller that is in the Area Admin, use asp-area="Admin"
<a asp-area="Admin" asp-controller="Usuario" asp-action="Index">Listar Usuários</a>
In your example then HomeController is not in an Area , but in the Controllers folder in the project root.