Resolving "No report instance" Error

Environment

Product	Progress® Telerik® Reporting
Version	18.3.24.1112

Description

After upgrading a project to use the Progress® Telerik® Reporting 2024 Q4 (18.3.24.1112) version of the Telerik Reporting assemblies, the reports fail to load with a console error stating No report instance was found.

Cause

The problem is most commonly caused by custom JsonSerializerSettings specified in the AddNewtonsoftJson method which interferes with the serialization process required for the Telerik Reporting to function properly.

Solution

To resolve the No report instance error, consider one of the following approaches:

Using Default JsonSerializerSettings

Update the AddNewtonsoftJson method in the Program.cs file of the project to use the default JsonSerializerSettings:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddNewtonsoftJson();

Creating an Action Filter for custom JsonSerializerSettings

If using the default serializer settings is not an option due to application requirements, create an ActionFilter to customize the JsonSerializerSettings for the reports controller:

1. Implement the JsonConfigFilterAttribute ActionFilter:

   using Microsoft.AspNetCore.Mvc;
   using Microsoft.AspNetCore.Mvc.Filters;
   using Newtonsoft.Json;
   using Newtonsoft.Json.Serialization;
   using Microsoft.AspNetCore.Mvc.Formatters;
   using System.Buffers;
   using Microsoft.Extensions.Options;
   
   public class JsonConfigFilterAttribute : ActionFilterAttribute
   {
       public override void OnResultExecuting(ResultExecutingContext context)
       {
           if (context.Result is ObjectResult objectResult)
           {
               var serializerSettings = new JsonSerializerSettings
               {
                   NullValueHandling = NullValueHandling.Include,
                   DateTimeZoneHandling = DateTimeZoneHandling.Unspecified,
                   ContractResolver = new CamelCasePropertyNamesContractResolver()
               };
   
               var jsonOutputFormatter = new NewtonsoftJsonOutputFormatter(
                   serializerSettings,
                   ArrayPool<char>.Shared,
                   new MvcOptions { },
                   new MvcNewtonsoftJsonOptions()
                   );
   
               objectResult.Formatters.Add(jsonOutputFormatter);
           }
   
           base.OnResultExecuting(context);
       }
   }
   

2. Annotate the ReportsController with the newly created JsonConfigFilter attribute:

   [Route("api/[controller]")]
   [ApiController]
   [JsonConfigFilter]
   public class ReportsController : ReportsControllerBase
   {
       public ReportsController(IReportServiceConfiguration reportServiceConfiguration)
       : base(reportServiceConfiguration)
           {
           }
   }
   

See Also

• JsonSerializerSettings Documentation
• Understanding Action Filters in ASP.NET MVC
• NewtonsoftJsonOutputFormatter Class