public class ExceptionHandlerFilterAttribute :  ExceptionFilterAttribute
    {
        private readonly ILogger _logger;
        public ExceptionHandlerFilterAttribute(ILogger<ExceptionHandlerFilterAttribute> logger)
        {
            _logger = logger;
        }

        public override void OnException(ExceptionContext context)
        {
            _logger.LogError(context.Exception, $"Error during {context.HttpContext.Request.Path}");
            if (!(context.Exception is IHasUserMessageException))
            {
                context.Result = new StatusCodeResult(StatusCodes.Status500InternalServerError);
                return;
            }

            switch (context.Exception)
            {
                case ValidationException e:
                    context.Result = new BadRequestObjectResult(new { Success = false, ErrorMessage = e.Message});
                    break;
                case HashCollisionException e:
                    context.Result = new ConflictObjectResult(new { Success = false, ErrorMessage = e.Message });
                    break;
                case InvalidMessageFormatException e:
                    context.Result = new BadRequestObjectResult(new { Success = false, ErrorMessage = e.Message });
                    break;
                case EventTimedOutValidationException e:
                    context.Result = new BadRequestObjectResult(new { Success = false, ErrorMessage = e.Message });
                    break;
                case InconsistentInputDataException e:
                    context.Result = new BadRequestObjectResult(new { Success = false, ErrorMessage = e.Message });
                    break;
                case UnauthorizedException e:
                    context.Result = new ObjectResult(new { Success = false, ErrorMessage = e.Message }) { StatusCode = StatusCodes.Status401Unauthorized };
                    break;
                default:
                    context.Result = new BadRequestObjectResult(new { Success = false, ErrorMessage = context.Exception });
                    break;
            }
        }
    }


  [Route("api/[controller]")]
    [ServiceFilter(typeof(ExceptionHandlerFilterAttribute))]

    public class EventsController : ControllerBase
    {......}