diff --git a/src/Controller/MapApiController.php b/src/Controller/MapApiController.php
index 85177bc..8624c66 100644
--- a/src/Controller/MapApiController.php
+++ b/src/Controller/MapApiController.php
@@ -4,11 +4,15 @@ namespace App\Controller;
 
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\HttpKernel\Exception\UnprocessableEntityHttpException;
 use Symfony\Component\Routing\Annotation\Route;
 
-use Doctrine\Persistence\ManagerRegistry;
 use Doctrine\Common\Collections\ArrayCollection;
 
+use Exception;
+use ValueError;
+
 use App\Repository\SiteRepository;
 use App\Repository\FloorRepository;
 use App\Repository\PlaceRepository;
@@ -26,7 +30,7 @@ class MapApiController extends AbstractController
 {
     //function get_Name($rep) {return $rep->getName();}
 
-    #[Route('/map/api/test')]
+    #[Route('/api/map/test')]
     public function test(PlaceNameRepository $pNRep, RoomUserNameRepository $uNRep, PlaceRepository $pRep, SiteRepository $sRep): JsonResponse
     {
         $place0 = $pRep->findPlaceById(1)[0];
@@ -42,13 +46,14 @@ class MapApiController extends AbstractController
         ]);
     }
 
-    #[Route('/map/api/get_floor/{id}/{representation}')]
+    #[Route('/api/map/get_floor/{id}/{representation}')]
     public function get_floor(FloorRepository $rep, int $id, string $representation='Cylinder'): JsonResponse
     {
         //id is the floor's id, representation being Cylinder or PolySurface or other if implemented
         //it defines which representation should we use to project it on 2 dimension
         $floors = $rep->findFloorById($id);
-        if (sizeof($floors)!=1) { return $this->json(["Error : None or Too Many Floors have this id"]); }
+        if (sizeof($floors)==0){ throw new NotFoundHttpException('Error: '.$id.' doesn\'t correspond to any floor.'); }
+        elseif (sizeof($floors)>1) { throw new Exception('Internal Error: '.$id.' refers to more than one floorId ; the BDD is corrupted.'); }
         $floor = $floors[0];
         $places = $floor->getPlaces();
         $jsonPlaces = new ArrayCollection();
@@ -68,11 +73,12 @@ class MapApiController extends AbstractController
         return $this->json($jsonPlaces->toArray());
     }
 
-    #[Route('/map/api/find_place_by_name/{name}')]
+    #[Route('/api/map/find_place_by_name/{name}')]
     public function find_place_by_name(PlaceRepository $rep, string $name): JsonResponse
     {
         $places = $rep->findPlaceByName($name);
-        if (sizeof($places)!=1) { return $this->json([0]); }
+        if (sizeof($places)==0){ throw new NotFoundHttpException('Error: \''.$name.'\' doesn\'t correspond to any placeName.'); }
+        elseif (sizeof($places)>1) { throw new UnprocessableEntityHttpException('Error: \''.$name.'\' refers to more than one place ; the API can\'t decide which one should be provided.'); }
         else {
             $place = $places[0];
             $floorsId = array();
@@ -87,13 +93,12 @@ class MapApiController extends AbstractController
     }
 
 
-    #[Route('/map/api/show_place_info/{id}')]
+    #[Route('/api/map/show_place_info/{id}')]
     public function show_place_info(PlaceRepository $rep, int $id): JsonResponse
     {
         $places = $rep->findPlaceById($id);
-        if (sizeof($places)!=1) {
-            return $this->json([0]);
-        }
+        if (sizeof($places) == 0) { throw new NotFoundHttpException('Error: '.$id.' doesn\'t correspond to any place.'); }
+        elseif (sizeof($places)>1) { throw new Exception('Internal Error: '.$id.' refers to more than one placeId ; the BDD is corrupted.'); }
         else {
             return $this->json([
                 'idPlace' => $places[0]->getId(),
@@ -103,13 +108,11 @@ class MapApiController extends AbstractController
         }
     }
 
-    #[Route('/map/api/get_all_editions')]
+    #[Route('/api/map/get_all_editions')]
     public function getEditions(EditionRepository $rep): JsonResponse
     {
         $edits = $rep->getAllEditions();
-        if (sizeof($edits)<1) {
-            return $this->json([0]);
-        }
+        if (sizeof($edits)<1) { throw new NotFoundHttpException('Warning: There is no more edition to check.'); }
         else {
             $listEdits = array();
             foreach ($edits as $edit){
@@ -125,34 +128,36 @@ class MapApiController extends AbstractController
         return $this->json($listEdits);
     }
 
-    #[Route('/map/api/create_edition/{mode}/{placeId}/{value}')]
+    #[Route('/api/map/create_edition/{mode}/{placeId}/{value}')]
     public function createEdition(EditionRepository $Erep, PlaceRepository $Prep, string $mode, int $placeId, string $value): JsonResponse
     {
         //mode is the type of modification, can be AddPlaceName ; DelPlaceName ; AddRoomUserName or DelRoomUserName
         $edit = new Edition();
-        if ($edit->initEdition($Prep, $mode, $placeId, $value) == null) {return $this->json(["Error during initEdition : None or Too Many Places found with id"]);}
+        $edit->initEdition($Prep, $mode, $placeId, $value);
         $Erep->add($edit, true);
         return $this->json(["added"]);
     }
 
-    #[Route('/map/api/remove_edition/{id}')]
+    #[Route('/api/map/remove_edition/{id}')]
     public function removeEdition(EditionRepository $rep, int $id): JsonResponse
     {
         $edit = $rep->findEditionById($id);
-        if (sizeof($edit) == 0) {return $this->json([0]);}
+        if (sizeof($edit) == 0) {throw new NotFoundHttpException('Error: '.$id.' doesn\'t correspond to any edit.'); }
+        elseif (sizeof($places)>1) { throw new Exception('Internal Error: '.$id.' refers to more than one edit ; the BDD is corrupted.'); }
         $rep->remove($edit[0], true);
         return $this->json(["removed"]);
     }
 
-    #[Route('/map/api/add_place_name/{placeId}/{value}')]
+    #[Route('/api/map/add_place_name/{placeId}/{value}')]
     public function addPlaceName(PlaceRepository $pRep, PlaceNameRepository $pNRep, int $placeId, string $value): JsonResponse 
     {
         $places = $pRep->findPlaceById($placeId);
-        if (sizeof($places) != 1) { return $this->json([0]); }
+        if (sizeof($places) == 0) { throw new NotFoundHttpException('Error: '.$placeId.' doesn\'t correspond to any place.'); }
+        elseif (sizeof($places)>1) { throw new Exception('Internal Error: '.$placeId.' refers to more than one placeId ; the BDD is corrupted.'); }
         else{
             $names = new ArrayCollection();
             foreach($places[0]->getNames() as $plName) { $names[] = $plName->getName(); }
-            if ($names->contains($value)) { return $this->json([2]); }
+            if ($names->contains($value)) { throw new ValueError('Warning: \''.$value.'\' is already a name for place '.$placeId);}
             else {
                 $pN = new PlaceName();
                 $pN->setPlace($places[0]);
@@ -162,25 +167,26 @@ class MapApiController extends AbstractController
             }
         }
     }
-    #[Route('/map/api/del_place_name/{placeId}/{value}')]
+    #[Route('/api/map/del_place_name/{placeId}/{value}')]
     public function delPlaceName(PlaceNameRepository $pNRep, int $placeId, string $value): JsonResponse 
     {
         $pN = $pNRep->findPlaceName($placeId, $value);
-        if (sizeof($pN)==0) { return $this->json([0]); }
+        if (sizeof($pN)==0) { throw new NotFoundHttpException('Error: \''.$value.'\' isn\'t registered as a name for the place '.$placeId);  }
         $pNRep->remove($pN[0], true);
         return $this->json(["removed"]);
     }
     
 
-    #[Route('/map/api/add_room_user_name/{placeId}/{value}')]
-    public function addRoomUserName(PlaceRepository $pRep, RoomUserNameRepository $rURep, ManagerRegistry $mr, int $placeId, string $value): JsonResponse 
+    #[Route('/api/map/add_room_user_name/{placeId}/{value}')]
+    public function addRoomUserName(PlaceRepository $pRep, RoomUserNameRepository $rURep, int $placeId, string $value): JsonResponse 
     {
         $places = $pRep->findPlaceById($placeId);
-        if (sizeof($places) != 1) { return $this->json([0]); }
+        if (sizeof($places) == 0) { throw new NotFoundHttpException('Error: '.$placeId.' doesn\'t correspond to any placeId.'); }
+        elseif (sizeof($places)>1) { throw new Exception('Internal Error: '.$placeId.' refers to more than one placeId ; the BDD is corrupted.'); }
         else{
             $names = new ArrayCollection();
             foreach($places[0]->getRoomUsers() as $rUser) { $names[] = $rUser->getUserName(); }
-            if ($names->contains($value)) { return $this->json([2]); }
+            if ($names->contains($value)) { throw new ValueError('Warning: \''.$value.'\' is already a name for place '.$placeId);}
             else {
                 $rU = new RoomUserName();
                 $rU->setPlace($places[0]);
@@ -190,11 +196,11 @@ class MapApiController extends AbstractController
             }
         }
     }
-    #[Route('/map/api/del_room_user_name/{placeId}/{value}')]
+    #[Route('/api/map/del_room_user_name/{placeId}/{value}')]
     public function delRoomUserName(RoomUserNameRepository $uRep, int $placeId, string $value): JsonResponse 
     {
         $rU = $uRep->findRoomUserName($placeId, $value);
-        if (sizeof($rU)==0) { return $this->json([0]); }
+        if (sizeof($rU)==0) { throw new NotFoundHttpException('Error: \''.$value.'\' isn\'t registered as a user for the place '.$placeId); }
         $uRep->remove($rU[0], true);
         return $this->json(["removed"]);
     }
diff --git a/src/Entity/Edition.php b/src/Entity/Edition.php
index bae0f74..8aea88c 100644
--- a/src/Entity/Edition.php
+++ b/src/Entity/Edition.php
@@ -7,6 +7,8 @@ use App\Repository\PlaceRepository;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
+use Exception;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 #[ORM\Entity(repositoryClass: EditionRepository::class)]
 class Edition
@@ -60,7 +62,8 @@ class Edition
     public function initEdition(PlaceRepository $rep, string $mode, int $id, string $val): self
     {
         $places = $rep->findPlaceById($id);
-        if (sizeof($places)!=1) { return null; }
+        if (sizeof($places) == 0) { throw new NotFoundHttpException('Error: '.$id.' doesn\'t correspond to any place.'); }
+        elseif (sizeof($places)>1) { throw new Exception('Internal Error: '.$id.' refers to more than one placeId ; the BDD is corrupted.'); }
         $this->mode = $mode;
         $this->editedPlace = $places[0];
         $this->val = $val;