public IActionResult GetCertificate(int courseId) { var course = courseService.Get(courseId); course = null; var email = User.FindFirst("Email"); var user = userService.Get(email.Value); if (course == null || user == null) { return(View(nameof(Index))); } try { string file_type = "application/pdf"; string file_name = "certificate.pdf"; return(File(certificateService.CreateFilePDF(course.CourseId, user.UserId), file_type, file_name)); } catch (ValidationException ex) { ModelState.AddModelError("", ex.Message); return(View(nameof(Index))); } }