Asp.net核心IIS 8.5：找不到视图“索引”

3个应用程序,前端,API和登录(在同一站点上);

所有3个都在VS2015的IIS Express中完美地工作;

前端(只有html / AngularJS)& API在IIS 8.5上运行良好

但是对于Login(IdentityServer4)：

InvalidOperationException: The view 'Index' was not found. The following locations were searched:
 - ~/UI/Home/Views/Index.cshtml
 - ~/UI/SharedViews/Index.cshtml

我明白’?/’是指批准;

我的VS2015结构：

经测试/检查：

Program.cs中的.UseContentRoot(Directory.GetCurrentDirectory())
>服务器上IIS_IUSRS用户帐户的所有权限
> CustomViewLocationExpander：

public class CustomViewLocationExpander : IViewLocationExpander {

   public IEnumerable<string> ExpandViewLocations(ViewLocationExpanderContext context,IEnumerable<string> viewLocations){
       yield return "~/UI/{1}/Views/{0}.cshtml";
       yield return "~/UI/SharedViews/{0}.cshtml";
   }

   public void PopulateValues(ViewLocationExpanderContext context)
   {
   }
}

我可以在’wwwroot’上免费访问所有内容js / images / css

我对这一点毫无头绪.