diff --git a/errors/errors.go b/errors/errors.go
index 33063a4b..77e44dd3 100644
--- a/errors/errors.go
+++ b/errors/errors.go
@@ -16,9 +16,11 @@ func (e *Error) Error() string {
 }
 
 var (
-	RecordExists  = errors.New("Record already exists!")
+	RecordExists = errors.New("Record already exists!")
+
 	NotAuthorized = errors.New(i18n.Authorization["notAuthorized"]["it"])
-	SchoolExists  = &Error{
+
+	SchoolExists = &Error{
 		TemplateName: "error_school_exists",
 		Err:          errors.New(i18n.Errors["schoolExists"]["it"]),
 	}
@@ -27,8 +29,14 @@ var (
 		TemplateName: "error_category_exists",
 		Err:          errors.New(i18n.FlashMessages["categoryExists"]["it"]),
 	}
+
 	OutOfTime = &Error{
 		TemplateName: "error_out_of_time",
 		Err:          errors.New(i18n.Errors["outOfTime"]["it"]),
 	}
+
+	ContestHasZeroQuestions = &Error{
+		TemplateName: "error_contest_has_zero_questions",
+		Err:          errors.New(i18n.Errors["contestHasZeroQuestions"]["it"]),
+	}
 )
diff --git a/handlers/compose/sql/oef_test.sql b/handlers/compose/sql/oef_test.sql
index 354456ab..e80c8f08 100644
--- a/handlers/compose/sql/oef_test.sql
+++ b/handlers/compose/sql/oef_test.sql
@@ -120,10 +120,10 @@ CREATE TABLE `participants` (
   `created_at` timestamp NULL DEFAULT NULL,
   `updated_at` timestamp NULL DEFAULT NULL,
   `deleted_at` timestamp NULL DEFAULT NULL,
-  `creator_id` varchar(255) DEFAULT NULL,
+  `creator_id` int(10) unsigned DEFAULT NULL,
   `creator_role` varchar(255) DEFAULT NULL,
   `creator_ip` varchar(255) DEFAULT NULL,
-  `updater_id` varchar(255) DEFAULT NULL,
+  `updater_id` int(10) unsigned DEFAULT NULL,
   `updater_role` varchar(255) DEFAULT NULL,
   `updater_ip` varchar(255) DEFAULT NULL,
   `user_id` int(10) unsigned DEFAULT NULL,
@@ -216,10 +216,10 @@ CREATE TABLE `responses` (
   `created_at` timestamp NULL DEFAULT NULL,
   `updated_at` timestamp NULL DEFAULT NULL,
   `deleted_at` timestamp NULL DEFAULT NULL,
-  `creator_id` varchar(255) DEFAULT NULL,
+  `creator_id` int(10) unsigned DEFAULT NULL,
   `creator_role` varchar(255) DEFAULT NULL,
   `creator_ip` varchar(255) DEFAULT NULL,
-  `updater_id` varchar(255) DEFAULT NULL,
+  `updater_id` int(10) unsigned DEFAULT NULL,
   `updater_role` varchar(255) DEFAULT NULL,
   `updater_ip` varchar(255) DEFAULT NULL,
   `name` varchar(255) DEFAULT NULL,
@@ -257,10 +257,10 @@ CREATE TABLE `schools` (
   `created_at` timestamp NULL DEFAULT NULL,
   `updated_at` timestamp NULL DEFAULT NULL,
   `deleted_at` timestamp NULL DEFAULT NULL,
-  `creator_id` varchar(255) DEFAULT NULL,
+  `creator_id` int(10) unsigned DEFAULT NULL,
   `creator_role` varchar(255) DEFAULT NULL,
   `creator_ip` varchar(255) DEFAULT NULL,
-  `updater_id` varchar(255) DEFAULT NULL,
+  `updater_id` int(10) unsigned DEFAULT NULL,
   `updater_role` varchar(255) DEFAULT NULL,
   `updater_ip` varchar(255) DEFAULT NULL,
   `name` varchar(255) DEFAULT NULL,
diff --git a/handlers/handlers_test.go b/handlers/handlers_test.go
index 8fa02ca1..a8421c42 100644
--- a/handlers/handlers_test.go
+++ b/handlers/handlers_test.go
@@ -371,6 +371,7 @@ func (t *testSuite) TestSchoolSubscription() {
 
 		t.Equal(http.StatusSeeOther, rr.Code)
 
+		log.Println(rr.Header())
 		schoolId, err := getIdFromPath(rr.Header()["Location"][0])
 		if !t.Failed() {
 			doc, err := goquery.NewDocumentFromReader(rr.Body)
@@ -454,13 +455,14 @@ func (t *testSuite) TestUserModifier() {
 		t.Equal(http.StatusOK, rr.Code)
 
 		if !t.Failed() {
+			fmt.Println(rr.Body)
 			doc, err := goquery.NewDocumentFromReader(rr.Body)
 			if err != nil {
 				log.Fatal(err)
 			}
-			expected := "Creato da"
+			expected := "admin[administrator]"
 			ok := false
-			doc.Find("dt").Each(func(i int, s *goquery.Selection) {
+			doc.Find("dd").Each(func(i int, s *goquery.Selection) {
 				if strings.Contains(s.Text(), expected) {
 					ok = true
 				}
diff --git a/i18n/i18n.go b/i18n/i18n.go
index b805c615..9f22c08e 100644
--- a/i18n/i18n.go
+++ b/i18n/i18n.go
@@ -47,5 +47,8 @@ var (
 		"schoolExists": map[string]string{
 			"it": "Una scuola con questo codice meccanografico è già presente nella base dati!",
 		},
+		"contestHasZeroQuestions": map[string]string{
+			"it": "La gara a cui il partecipante è iscritto non contiene alcuna domanda.",
+		},
 	}
 )
diff --git a/orm/contest.go b/orm/contest.go
index 8530de45..1e09002c 100644
--- a/orm/contest.go
+++ b/orm/contest.go
@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"time"
 
+	"git.andreafazzi.eu/andrea/oef/errors"
 	"git.andreafazzi.eu/andrea/oef/renderer"
 	"github.com/dgrijalva/jwt-go"
 	"github.com/jinzhu/gorm"
@@ -92,7 +93,7 @@ func (c *Contest) ReadAll(db *Database, args map[string]string, w http.ResponseW
 	var contests []*Contest
 
 	claims := r.Context().Value("user").(*jwt.Token).Claims.(jwt.MapClaims)
-	
+
 	if claims["admin"].(bool) {
 		if err := db._db.Order("created_at").Find(&contests).Error; err != nil {
 			return nil, err
@@ -199,6 +200,10 @@ func (c *Contest) generateQuestionsOrder(db *gorm.DB) (string, error) {
 		return "", err
 	}
 
+	if len(questions) == 0 {
+		return "", errors.ContestHasZeroQuestions
+	}
+
 	count := 0
 	generated := make(map[int]bool, 0)
 
diff --git a/orm/participant.go b/orm/participant.go
index fb23ef5f..c9f81b12 100644
--- a/orm/participant.go
+++ b/orm/participant.go
@@ -78,6 +78,30 @@ func (model *Participant) String() string {
 	return fmt.Sprintf("%s %s", strings.ToUpper(model.Lastname), strings.Title(strings.ToLower(model.Firstname)))
 }
 
+func (model *Participant) SetCreatorID(id uint) {
+	model.CreatorID = id
+}
+
+func (model *Participant) SetCreatorRole(role string) {
+	model.CreatorRole = role
+}
+
+func (model *Participant) SetCreatorIP(addr string) {
+	model.CreatorIP = addr
+}
+
+func (model *Participant) SetUpdaterID(id uint) {
+	model.UpdaterID = id
+}
+
+func (model *Participant) SetUpdaterRole(role string) {
+	model.UpdaterRole = role
+}
+
+func (model *Participant) SetUpdaterIP(addr string) {
+	model.UpdaterIP = addr
+}
+
 // func setFlashMessage(w http.ResponseWriter, r *http.Request, key string) error {
 // 	session, err := store.Get(r, "flash-session")
 // 	if err != nil {
@@ -210,7 +234,7 @@ func (model *Participant) Create(db *Database, args map[string]string, w http.Re
 			return nil, errors.CategoryExists
 		}
 
-		participant.CreatorID = getUserIDFromTokenAsUint(r)
+		WriteCreator(r, participant)
 
 		participant, err = CreateParticipant(db, participant)
 		if err != nil {
@@ -362,11 +386,11 @@ func (model *Participant) Update(db *Database, args map[string]string, w http.Re
 			return nil, errors.CategoryExists
 		}
 
-		if err := db._db.Where(participant.(*Participant).ContestIDs).Find(&participant.(*Participant).Contests).Error; err != nil {
+		if err := db._db.Where([]uint(participant.(*Participant).ContestIDs)).Find(&participant.(*Participant).Contests).Error; err != nil {
 			return nil, err
 		}
 
-		participant.(*Participant).UpdaterID = getUserIDFromTokenAsUint(r)
+		WriteUpdater(r, participant.(*Participant))
 
 		_, err = SaveParticipant(db, participant)
 		if err != nil {
diff --git a/orm/response.go b/orm/response.go
index 4e48457a..3a71d143 100644
--- a/orm/response.go
+++ b/orm/response.go
@@ -63,6 +63,30 @@ func (model *Response) IsActive() bool {
 	return !time.Now().After(model.Contest.EndTime) || model.Contest.isAlwaysActive()
 }
 
+func (model *Response) SetCreatorID(id uint) {
+	model.CreatorID = id
+}
+
+func (model *Response) SetCreatorRole(role string) {
+	model.CreatorRole = role
+}
+
+func (model *Response) SetCreatorIP(addr string) {
+	model.CreatorIP = addr
+}
+
+func (model *Response) SetUpdaterID(id uint) {
+	model.UpdaterID = id
+}
+
+func (model *Response) SetUpdaterRole(role string) {
+	model.UpdaterRole = role
+}
+
+func (model *Response) SetUpdaterIP(addr string) {
+	model.UpdaterIP = addr
+}
+
 func (model *Response) generateAnswersIDs() string {
 	ids := make([]string, 0)
 	for _, sr := range model.SingleResponses {
@@ -93,7 +117,7 @@ func (model *Response) Create(db *Database, args map[string]string, w http.Respo
 			return nil, err
 		}
 
-		response.CreatorID = getUserIDFromTokenAsUint(r)
+		WriteCreator(r, response)
 
 		response, err = CreateResponse(db, response)
 		if err != nil {
@@ -210,7 +234,7 @@ func (model *Response) Update(db *Database, args map[string]string, w http.Respo
 			return nil, err
 		}
 
-		response.(*Response).UpdaterID = getUserIDFromTokenAsUint(r)
+		WriteUpdater(r, response.(*Response))
 
 		_, err = SaveResponse(db, response)
 		if err != nil {
diff --git a/orm/school.go b/orm/school.go
index 88801b79..78777406 100644
--- a/orm/school.go
+++ b/orm/school.go
@@ -30,6 +30,8 @@ https://iscrizioni.olimpiadi-economiaefinanza.it/
 
 ed inserire le credenziali riportate sopra (si consiglia di effettuare un copia/incolla).
 
+Questa mail è stata generata da un sistema automatico. Si prega di non rispondere.
+
 Cordialmente,
 Lo Staff delle OEF 2020.
 `
@@ -91,6 +93,30 @@ func (model *School) To() string {
 	return model.Email
 }
 
+func (model *School) SetCreatorID(id uint) {
+	model.CreatorID = id
+}
+
+func (model *School) SetCreatorRole(role string) {
+	model.CreatorRole = role
+}
+
+func (model *School) SetCreatorIP(addr string) {
+	model.CreatorIP = addr
+}
+
+func (model *School) SetUpdaterID(id uint) {
+	model.UpdaterID = id
+}
+
+func (model *School) SetUpdaterRole(role string) {
+	model.UpdaterRole = role
+}
+
+func (model *School) SetUpdaterIP(addr string) {
+	model.UpdaterIP = addr
+}
+
 func (model *School) exists(db *Database) (*User, error) {
 	var user User
 	if err := db._db.First(&user, &User{Username: model.Username()}).Error; err != nil && err != gorm.ErrRecordNotFound {
@@ -165,9 +191,7 @@ func (model *School) Create(db *Database, args map[string]string, w http.Respons
 			return nil, err
 		}
 
-		school.CreatorID = getUserIDFromTokenAsUint(r)
-		school.CreatorRole = getUserRole(r)
-		school.CreatorIP = r.RemoteAddr
+		WriteCreator(r, school)
 
 		school.mailSender = mail.NewMailSender(db.Config, mailBody)
 		school, err = CreateSchool(db, school)
@@ -238,12 +262,7 @@ func (model *School) Update(db *Database, args map[string]string, w http.Respons
 			return nil, err
 		}
 
-		// FIXME
-		// WriteCreator(school.(*School))
-
-		school.(*School).UpdaterID = getUserIDFromTokenAsUint(r)
-		school.(*School).UpdaterRole = getUserRole(r)
-		school.(*School).UpdaterIP = r.RemoteAddr
+		WriteUpdater(r, school.(*School))
 
 		_, err = SaveSchool(db, school)
 		if err != nil {
diff --git a/orm/usermodifier.go b/orm/usermodifier.go
index f90df8c8..c678af32 100644
--- a/orm/usermodifier.go
+++ b/orm/usermodifier.go
@@ -1,5 +1,7 @@
 package orm
 
+import "net/http"
+
 type Modifier interface {
 	SetCreatorID(id uint)
 	SetUpdaterID(id uint)
@@ -45,3 +47,16 @@ func (um UserModifier) UpdatedBy() *User {
 
 	return um.Updater
 }
+
+func WriteCreator(r *http.Request, modifier Modifier) {
+	modifier.SetCreatorID(getUserIDFromTokenAsUint(r))
+	modifier.SetCreatorRole(getUserRole(r))
+	modifier.SetCreatorIP(r.RemoteAddr)
+
+}
+
+func WriteUpdater(r *http.Request, modifier Modifier) {
+	modifier.SetUpdaterID(getUserIDFromTokenAsUint(r))
+	modifier.SetUpdaterRole(getUserRole(r))
+	modifier.SetUpdaterIP(r.RemoteAddr)
+}
diff --git a/templates/error_contest_has_zero_questions.html.tpl b/templates/error_contest_has_zero_questions.html.tpl
new file mode 100644
index 00000000..f1c949c4
--- /dev/null
+++ b/templates/error_contest_has_zero_questions.html.tpl
@@ -0,0 +1,11 @@
+{{ define "content" }}
+<div class="container">
+  <h1 class="border-bottom">Errore</h1>
+  <p>
+    Si è verificato un errore durante la creazione o l'aggiornamento di un partecipante: <strong>{{.Data}}</strong>
+  </p>
+  <p>
+    Clicca {{all "Contest"|anchor "qui"}} per tornare all'elenco delle gare.
+  </p>
+</div>
+{{ end }}