specified method is not supported ?Please Help

var query = (from r in context.JobSeekerRegistration
        select new
        {
            ID = r.ID,
            RegistrationNumber = r.RegistrationNumber,
            NCOCode = r.NCOCategory.Name != null ? r.NCOCategory.Name:
                    r.JobSeekerWorkDetails.OrderByDescending(a=>a.JobSeekerID).
                    FirstOrDefault().NCOCategory.Name,
            Status = r.ApplicationStatus.Status,
            Name = r.Name,
            CreatedOn = r.CreatedOn,
            StatusID = r.StatusID,
            LocationID = r.LocationID
         });