Error executing template "Designs/Swift/Navigation/BreadcrumbNavigation.cshtml"
System.InvalidOperationException: Sequence contains no elements
   at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
   at CompiledRazorTemplates.Dynamic.RazorEngine_9254788446ec4f5db06a40f0cc821f14.Execute() in D:\dynamicweb.net\Solutions\nextech\Superhome.swiftstaging.dynamicweb-cms.com\files\Templates\Designs\Swift\Navigation\BreadcrumbNavigation.cshtml:line 31
   at RazorEngine.Templating.TemplateBase.RazorEngine.Templating.ITemplate.Run(ExecuteContext context, TextWriter reader)
   at RazorEngine.Templating.RazorEngineService.RunCompile(ITemplateKey key, TextWriter writer, Type modelType, Object model, DynamicViewBag viewBag)
   at RazorEngine.Templating.RazorEngineServiceExtensions.<>c__DisplayClass16_0.<RunCompile>b__0(TextWriter writer)
   at RazorEngine.Templating.RazorEngineServiceExtensions.WithWriter(Action`1 withWriter)
   at Dynamicweb.Rendering.RazorTemplateRenderingProvider.Render(Template template)
   at Dynamicweb.Rendering.TemplateRenderingService.Render(Template template)
   at Dynamicweb.Rendering.Template.RenderRazorTemplate()


  1     @inherits Dynamicweb.Rendering.ViewModelTemplate<Dynamicweb.Frontend.Navigation.NavigationTreeViewModel>
  2     
  3     @if (!Pageview.IsVisualEditorMode)
  4     {
  5     	string menuId = Model.Parameters.ContainsKey("menu-id") ? $"menu_{Model.Parameters["menu-id"].ToString().ToLower()}" : string.Empty;
  6     	bool showProductInBreadcrumb = Model.Parameters.ContainsKey("showProductInBreadcrumb") ? Dynamicweb.Core.Converter.ToBoolean(Model.Parameters["showProductInBreadcrumb"]) : false;
  7     
  8     	<ol class="breadcrumb small mb-0 @menuId">
  9     		@{
 10     			var breadCrumbNavigationTree = new Stack<Dynamicweb.Frontend.Navigation.NavigationTreeNodeViewModel>(Model.Nodes);
 11     			while (breadCrumbNavigationTree.Count > 0)
 12     			{
 13     				var currentNode = breadCrumbNavigationTree.Pop();
 14     				if (currentNode.ShowInBreadcrumb)
 15     				{
 16     					if (!string.IsNullOrEmpty(currentNode.Link))
 17     					{
 18     						<li class="breadcrumb-item">
 19     							<a href="@currentNode.Link">
 20     								@currentNode.Name
 21     							</a>
 22     						</li>
 23     					}
 24     					else
 25     					{
 26     						<li class="breadcrumb-item">
 27     							@currentNode.Name
 28     						</li>
 29     					}
 30     				}
 31     <h1>@currentNode.Nodes.First().Name</h1>
 32     
 33     				foreach (var nextNode in currentNode.Nodes)
 34     				{
 35     					breadCrumbNavigationTree.Push(nextNode);
 36     				}
 37     			}
 38     		}
 39     		@if (showProductInBreadcrumb && !string.IsNullOrEmpty(Dynamicweb.Context.Current.Request.QueryString["ProductID"]))
 40     		{
 41     			string productid = Dynamicweb.Context.Current.Request.QueryString["ProductID"];
 42     			string variantid = Dynamicweb.Context.Current.Request.QueryString["VariantID"];
 43     			var product = Dynamicweb.Ecommerce.Services.Products.GetProductById(productid, variantid, Dynamicweb.Ecommerce.Common.Context.LanguageID);
 44     			if (product != null)
 45     			{
 46     				<li class="breadcrumb-item">
 47     					@product.Name
 48     				</li>
 49     			}
 50     		}
 51     	</ol>
 52     }
 53     else if (Model.Nodes.Count() < 2)
 54     {
 55     	<div class="alert alert-dark m-0" role="alert">
 56     		<span>@Translate("Breadcrumb navigation: The navigation will be shown here, if any")</span>
 57     	</div>
 58     }
 59