Can't add area on ASP.NET Core MVC project

[chrgraefe]

Describe the bug

A clear and concise description of what the bug is.

To Reproduce

Steps to reproduce the behavior:

1. Using this version of ASP.NET Core '3.0.100-preview-009812'
2. New ASP.NET Core MVC project in VS2019 Preview
3. Can't add area

Expected behavior

A dialog to type area name

[barrytang]

To report new issues, use the Report a Problem tool. The GitHub Issue Tracker for the aspnet/Tooling repo is now deprecated in favor of the Report a Problem tool.

If you encounter a problem with Visual Studio, we want to know about it so that we can diagnose and fix it. By using the Report a Problem tool, you can collect detailed information about the problem, and send it to Microsoft with just a few button clicks. See here for more details.

[barrytang]

/cc @seancpeters and @vijayrkn.