Answer by Celal Yildirim for Failed to bind to address (already in use) error with Visual Studio Mac API

The port 5001 has already used in your system. Change port number to 5002 or whatever you want.

You can add port number with .UseUrls into CreateWebHostBuilder

  public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>        WebHost.CreateDefaultBuilder(args)            .UseUrls("http://localhost:5002")            .UseStartup<Startup>();

Or if you use visual studio code, just replace args section in .vscode -> launch.json.

"args": ["urls=http://localhost:5002"]