Update Index.cshtml.cs

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml.cs

@@ -575,7 +575,7 @@ private async Task ConvertDocumentContentToHtmlAsync()
             Document.Content = content;
         }
 
-        protected async Task OnSectionRenderingErrorAsync(Exception e)
+        protected virtual async Task OnSectionRenderingErrorAsync(Exception e)
         {
             var message = $"Error occurred during the rendering of this document. The document is not valid: {e.Message}";
             Document.Content = $"````txt{Environment.NewLine}{message}{Environment.NewLine}````";