NullReferenceException reported when trying to view a product manually set in the dbo.UrlRecord table

Hello all,

Please can anyone help?

I am using version 4.30.

I created a record manually in the dbo.Product  table and then created an associated record in the dbo.UrlRecord table (ensuring there are no invalid characters in the Slug column).

When I do a search and click on the product in the Public Store, I expect my product page to be displayed but instead get the following error (It looks like the ProductReviewOverview object is set to Null):

NullReferenceException: Object reference not set to an instance of an object.
AspNetCore.Views_Product__Microdata.ExecuteAsync() in _Microdata.cshtml
+
   30.         <meta itemprop="reviewCount" content="@Model.ProductReviewOverview.TotalReviews"/>
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, bool invokeViewStarts)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.RenderPartialCoreAsync(string partialViewName, object model, ViewDataDictionary viewData, TextWriter writer)
Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.PartialAsync(string partialViewName, object model, ViewDataDictionary viewData)
AspNetCore.Views_Product__Microdata.ExecuteAsync() in _Microdata.cshtml
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   59.     @await Html.PartialAsync("_Microdata", product, dataAccociatedType)        
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, bool invokeViewStarts)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.RenderPartialCoreAsync(string partialViewName, object model, ViewDataDictionary viewData, TextWriter writer)
Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.PartialAsync(string partialViewName, object model, ViewDataDictionary viewData)
AspNetCore.Themes_Avenue_Views_Product_ProductTemplate_Grouped+<>c__DisplayClass11_0+<<ExecuteAsync>b__1>d.MoveNext() in ProductTemplate.Grouped.cshtml
+
  79.              @await Html.PartialAsync("_Microdata", Model)
Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperExecutionContext.GetChildContentAsync(bool useCachedResult, HtmlEncoder encoder)
Microsoft.AspNetCore.Mvc.TagHelpers.RenderAtEndOfFormTagHelper.ProcessAsync(TagHelperContext context, TagHelperOutput output)
Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperRunner.<RunAsync>g__Awaited|0_0(Task task, TagHelperExecutionContext executionContext, int i, int count)
AspNetCore.Themes_Avenue_Views_Product_ProductTemplate_Grouped.ExecuteAsync() in ProductTemplate.Grouped.cshtml
+
  76.      <form asp-route="Product" asp-route-sename="@Model.SeName" method="post" id="product-details-form">
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, bool invokeViewStarts)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, string contentType, Nullable<int> statusCode)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, string contentType, Nullable<int> statusCode)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ActionContext actionContext, IView view, ViewDataDictionary viewData, ITempDataDictionary tempData, string contentType, Nullable<int> statusCode)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor.ExecuteAsync(ActionContext context, ViewResult result)
Microsoft.AspNetCore.Mvc.ViewResult.ExecuteResultAsync(ActionContext context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|29_0<TFilter, TFilterAsync>(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext<TFilter, TFilterAsync>(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
WebMarkupMin.AspNetCore3.WebMarkupMinMiddleware.ProcessAsync(HttpContext context, bool useMinification, bool useCompression)
WebMarkupMin.AspNetCore3.WebMarkupMinMiddleware.ProcessAsync(HttpContext context, bool useMinification, bool useCompression)
WebMarkupMin.AspNetCore3.WebMarkupMinMiddlewareBase.Invoke(HttpContext context)
StackExchange.Profiling.MiniProfilerMiddleware.Invoke(HttpContext context) in MiniProfilerMiddleware.cs
Nop.Services.Authentication.AuthenticationMiddleware.Invoke(HttpContext context) in AuthenticationMiddleware.cs
Microsoft.AspNetCore.Localization.RequestLocalizationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
Nop.Services.Installation.InstallUrlMiddleware.Invoke(HttpContext context, IWebHelper webHelper) in InstallUrlMiddleware.cs
Nop.Services.Common.KeepAliveMiddleware.Invoke(HttpContext context, IWebHelper webHelper) in KeepAliveMiddleware.cs
Microsoft.AspNetCore.ResponseCompression.ResponseCompressionMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.HandleException(HttpContext context, ExceptionDispatchInfo edi)
Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

This only happens for Grouped Products (i.e. Products with ProductTypeID = 10)

I have now fully understood the issue after running it under debug.

First thing to note is that the exception stack is reporting on the wrong line, the actual line the crash occurs in is :

Line 34:  <meta itemprop="url" content="@Url.RouteUrl("Product", new { SeName = Model.SeName }, webHelper.CurrentRequestProtocol).ToLowerInvariant()"/>

Maybe the nopCommerce developers might want to consider fixing that.

Second thing is my crash was occurring because despite having a Url record for the Grouped Product parent , I didn't add url record's for any of the Grouped product child records. This was because the Product records for the children had the 'VisibleIndividually' flag set to 0.

I believe the fix to the bug is that when the child record has the VisibleIndividually flag set to zero, the code should not create an object based on the (blank) seoname as currently happens on line 34 in the _Microdata.cshtml file.

Thank you.