Accouplement de liaison et dérivation

Error executing template "Designs/Swift/Paragraph/Swift_ProductComponentParagraph.cshtml"
System.ArgumentNullException: Value cannot be null.
Parameter name: source
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
at Dynamicweb.Content.PageService.GetPageOrLanguage(Int32 pageId, Int32 areaId)
at CompiledRazorTemplates.Dynamic.RazorEngine_541a61f89b3649d59818217bd9bbd496.Execute() in D:\dynamicweb.net\Solutions\Dynamicweb\hctswift.cloud.dynamicweb-cms.com\files\Templates\Designs\Swift\Paragraph\Swift_ProductComponentParagraph.cshtml:line 7
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.ParagraphViewModel>
  2  3     @{
  4     	int itemSourcePageId = Convert.ToInt32(Model.Item.GetRawValueString("ComponentSource", "0"));
  5  6     	var pageService = new Dynamicweb.Content.PageService();
  7     	itemSourcePageId = itemSourcePageId > 0 && pageService.GetPageOrLanguage(itemSourcePageId, Pageview.AreaID) != null ? pageService.GetPageOrLanguage(itemSourcePageId, Pageview.AreaID).ID : itemSourcePageId;
  8     }
  9 10     @if (itemSourcePageId != 0) {
 11     	var page = Dynamicweb.Content.Services.Pages.GetPage(itemSourcePageId);
 12 13     	if (page != null) {
 14     		var pageViewModel = Dynamicweb.Frontend.ContentViewModelFactory.CreatePageInfoViewModel(page);
 15     		string itemTheme = !string.IsNullOrWhiteSpace(pageViewModel.Item.GetRawValueString("Theme")) ? " theme " + pageViewModel.Item.GetRawValueString("Theme").Replace(" ", "").Trim().ToLower() : string.Empty;
 16 17     		string contentPadding = pageViewModel.Item.GetRawValueString("ContentPadding", "");
 18     		contentPadding = contentPadding == "none" ? "p-0" : contentPadding;
 19     		contentPadding = contentPadding == "small" ? "p-2 p-md-3" : contentPadding;
 20     		contentPadding = contentPadding == "large" ? "p-4 p-md-5" : contentPadding;
 21     		contentPadding = contentPadding == "small-x" ? "px-2 px-md-3" : contentPadding;
 22     		contentPadding = contentPadding == "large-x" ? "px-4 px-md-5" : contentPadding;
 23 24     		string layout = Model.Item.GetRawValueString("Layout", "top");
 25     		switch (layout)
 26     		{
 27     			case "top":
 28     			case "alignLeftMiddle":
 29     				layout = "";
 30     				break;
 31     			case "center":
 32     			case "alignLeft":
 33     				layout = "d-flex align-items-center text-start";
 34     				break;
 35     		}
 36 37     		<div class="@contentPadding @itemTheme @(layout) h-100 item_@Model.Item.SystemName.ToLower()">
 38     			<div class="w-100">
 39     				@RenderGrid(itemSourcePageId)
 40     			</div>
 41     		</div>
 42     	} else if (Pageview.IsVisualEditorMode) {
 43     		<div class="alert alert-dark m-0" role="alert">
 44     			<span>@Translate("The selected component does not exist anymore")</span>
 45     		</div>
 46     	}
 47     } else if (Pageview.IsVisualEditorMode) {
 48     	<div class="alert alert-dark m-0" role="alert">
 49     		<span>@Translate("Product component: The component will be shown here, if any")</span>
 50     	</div>
 51     }
 52