In Blazor Hosted template, use Json.NET. Fixes #7122

src/Components/Blazor/Templates/src/content/BlazorHosted-CSharp/BlazorHosted-CSharp.Server/BlazorHosted-CSharp.Server.csproj

@@ -12,6 +12,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Blazor.Server" Version="$(TemplateBlazorPackageVersion)" />
     <PackageReference Include="Microsoft.AspNetCore.Components.Server" Version="$(TemplateComponentsPackageVersion)" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="$(TemplateComponentsPackageVersion)" />
   </ItemGroup>
 
   <ItemGroup>

src/Components/Blazor/Templates/src/content/BlazorHosted-CSharp/BlazorHosted-CSharp.Server/Startup.cs

@@ -13,7 +13,7 @@ namespace BlazorHosted_CSharp.Server
         // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
         public void ConfigureServices(IServiceCollection services)
         {
-            services.AddMvc();
+            services.AddMvc().AddNewtonsoftJson();
             services.AddResponseCompression();
         }