Failed to convert a generic implementation for IPipelineBehavior

[shahabganji]

I have implemented a generic pipeline behavior for my query handlers like the one below:

 public sealed class ErrorHandlerBehaviour<TRequest, TResponse>
        : IPipelineBehavior<TRequest, ViewResult<TResponse>>
    {
         public async Task<ViewResult<TResponse>> Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate<ViewResult<TResponse>> next)
         { 
              return ViewResult.Fail();
         }
    }

and registered that in the container like:

services.Add( new ServiceDescriptor(
                typeof(IPipelineBehavior<,>), typeof(ErrorHandlerBehaviour<,>),
                context.ServiceLifetime));

I have defined a query and a query handler:

public class GetStudent : IRequest<ViewResult<Student>>
    {
        public Guid Id { get; set; }
        public bool ThrowError { get; set; }
    }

    public class GetStudentHandler : IRequestHandler<GetStudent, ViewResult<Student>>
    {
        public async Task<ViewResult<Student>> Handle(GetStudent request, CancellationToken cancellationToken)
        {
            if( request.ThrowError ) throw new ModelNotFoundException();

            return new Student(request.Id);
        }

        public IViewContext ViewContext { get; }
    }

but at the runtime when I want to send the query to via mediator instance I get the following error:

Implementation type 'ErrorHandlerBehaviour`2[GetStudent,ViewResult`1[Student]]' can't be converted to service type 'MediatR.IPipelineBehavior`2[GetStudent,ViewResult`1[Student]]

however when I explicitly define a pipeline behavior for that query handler it works but the generic one does not, is there something I have missed?