MVC core TempData Session has not been configured for this application or request.

解决方案

在Startup中添加下面语句：

public void ConfigureServices(IServiceCollection services)
{
    // Add CookieTempDataProvider after AddMvc and include ViewFeatures.
    // using Microsoft.AspNetCore.Mvc.ViewFeatures;
    services.AddSingleton<ITempDataProvider, CookieTempDataProvider>();
}

相关链接

1. Microsoft
2. DotnetCurry