diff --git a/client/src/pages/Teacher/Dashboard/Dashboard.tsx b/client/src/pages/Teacher/Dashboard/Dashboard.tsx
index 109a24f..7a8ead9 100644
--- a/client/src/pages/Teacher/Dashboard/Dashboard.tsx
+++ b/client/src/pages/Teacher/Dashboard/Dashboard.tsx
@@ -27,7 +27,8 @@ import {
     Tooltip,
     NativeSelect,
     CardContent,
-    styled
+    styled,
+    DialogContentText
 } from '@mui/material';
 import {
     Search,
@@ -62,6 +63,8 @@ const Dashboard: React.FC = () => {
     const [openAddRoomDialog, setOpenAddRoomDialog] = useState(false);
     const [newRoomTitle, setNewRoomTitle] = useState('');
     const { selectedRoom, selectRoom, createRoom } = useRooms();
+    const [errorMessage, setErrorMessage] = useState('');
+    const [showErrorDialog, setShowErrorDialog] = useState(false);
 
     // Filter quizzes based on search term
     // const filteredQuizzes = quizzes.filter(quiz =>
@@ -105,21 +108,25 @@ const Dashboard: React.FC = () => {
     }, []);
 
     const handleSelectRoom = (event: React.ChangeEvent<HTMLSelectElement>) => {
-        if (event.target.value === "add-room") {
+        if (event.target.value === 'add-room') {
             setOpenAddRoomDialog(true);
         } else {
             selectRoom(event.target.value);
         }
-      };
+    };
 
     const handleSubmitCreateRoom = async () => {
         if (newRoomTitle.trim()) {
-            await createRoom(newRoomTitle);
-            // reload the list of rooms
-            const userRooms = await ApiService.getUserRooms();
-            setRooms(userRooms as RoomType[]);
-            setOpenAddRoomDialog(false);
-            setNewRoomTitle('');
+            try {
+                await createRoom(newRoomTitle);
+                const userRooms = await ApiService.getUserRooms();
+                setRooms(userRooms as RoomType[]);
+                setOpenAddRoomDialog(false);
+                setNewRoomTitle('');
+            } catch (error) {
+                setErrorMessage(error instanceof Error ? error.message : "Erreur inconnue");
+                setShowErrorDialog(true);
+            }
         }
     };
 
@@ -391,10 +398,7 @@ const Dashboard: React.FC = () => {
 
             <div className="roomSelection">
                 <label htmlFor="select-room">Sélectionner une salle: </label>
-                <select
-                    value={selectedRoom?._id || ''}
-                    onChange={(e) => handleSelectRoom(e)}
-                >
+                <select value={selectedRoom?._id || ''} onChange={(e) => handleSelectRoom(e)}>
                     {/* <option value="">Sélectionner une salle</option> */}
                     {rooms.map((room) => (
                         <option key={room._id} value={room._id}>
@@ -426,6 +430,15 @@ const Dashboard: React.FC = () => {
                     <Button onClick={handleSubmitCreateRoom}>Créer</Button>
                 </DialogActions>
             </Dialog>
+            <Dialog open={showErrorDialog} onClose={() => setShowErrorDialog(false)}>
+                <DialogTitle>Erreur</DialogTitle>
+                <DialogContent>
+                    <DialogContentText>{errorMessage}</DialogContentText>
+                </DialogContent>
+                <DialogActions>
+                    <Button onClick={() => setShowErrorDialog(false)}>Fermer</Button>
+                </DialogActions>
+            </Dialog>
 
             <div className="search-bar">
                 <TextField
diff --git a/client/src/services/ApiService.tsx b/client/src/services/ApiService.tsx
index bb5ae32..a630898 100644
--- a/client/src/services/ApiService.tsx
+++ b/client/src/services/ApiService.tsx
@@ -482,31 +482,34 @@ class ApiService {
             return `Une erreur inattendue s'est produite.`;
         }
     }
-    public async createRoom(title: string): Promise<string | string> {
+    public async createRoom(title: string): Promise<string> {
         try {
             if (!title) {
-                throw new Error(`Le titre de la salle est requis.`);
+                throw new Error("Le titre de la salle est requis.");
             }
-
+    
             const url: string = this.constructRequestUrl(`/room/create`);
             const headers = this.constructRequestHeaders();
             const body = { title };
-
-            const result: AxiosResponse = await axios.post(url, body, { headers });
-
-            if (result.status !== 200) {
-                throw new Error(`La création de la salle a échoué. Status: ${result.status}`);
-            }
-
+    
+            const result = await axios.post<{ roomId: string }>(url, body, { headers });
             return `Salle créée avec succès. ID de la salle: ${result.data.roomId}`;
+    
         } catch (error) {
-            console.log("Error details: ", error);
             if (axios.isAxiosError(error)) {
                 const err = error as AxiosError;
-                const data = err.response?.data as { error: string } | undefined;
-                return data?.error || 'Erreur serveur inconnue lors de la création de la salle.';
+                
+                const serverMessage = (err.response?.data as { message?: string })?.message 
+                    || (err.response?.data as { error?: string })?.error
+                    || err.message;
+                
+                if (err.response?.status === 409) {
+                    throw new Error(serverMessage);
+                }
+                
+                throw new Error(serverMessage || "Erreur serveur inconnue");
             }
-            return `Une erreur inattendue s'est produite.`;
+            throw error;
         }
     }
 
diff --git a/server/__mocks__/AppError.js b/server/__mocks__/AppError.js
index 0073aa4..cb18755 100644
--- a/server/__mocks__/AppError.js
+++ b/server/__mocks__/AppError.js
@@ -1,8 +1,11 @@
 class AppError extends Error {
     constructor(message, statusCode) {
-        super(message);
-        this.statusCode = statusCode;
+      super(message);
+      this.statusCode = statusCode || 500;
+  
+      Object.setPrototypeOf(this, new.target.prototype);
+  
+      Error.captureStackTrace(this, this.constructor);
     }
-}
-
+  }
 module.exports = AppError;
diff --git a/server/constants/errorCodes.js b/server/constants/errorCodes.js
index 41147ae..6fcd129 100644
--- a/server/constants/errorCodes.js
+++ b/server/constants/errorCodes.js
@@ -103,9 +103,38 @@ exports.COPY_FOLDER_ERROR = {
     message: 'Une erreur s\'est produite lors de la copie du dossier.',
     code: 400
 }
-
-
-
+exports.ROOM_NOT_FOUND = {
+    message: 'Aucune salle portant cet identifiant n\'a été trouvé.',
+    code: 404
+}
+exports.ROOM_ALREADY_EXISTS = {
+    message: 'Une salle avec ce nom existe déjà',
+    code: 409
+};
+exports.UPDATE_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors de la mise à jour de la salle.',
+    code: 400
+}
+exports.DELETE_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors de la suppression de la salle.',
+    code: 400
+}
+exports.GETTING_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors de la récupération de la salle.',
+    code: 400
+}
+exports.MOVING_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors du déplacement de la salle.',
+    code: 400
+}
+exports.DUPLICATE_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors de la duplication de la salle.',
+    code: 400
+}
+exports.COPY_ROOM_ERROR = {
+    message: 'Une erreur s\'est produite lors de la copie de la salle.',
+    code: 400
+}
 
 
 
diff --git a/server/controllers/room.js b/server/controllers/room.js
index 9d7c3dc..51ebf2c 100644
--- a/server/controllers/room.js
+++ b/server/controllers/room.js
@@ -16,8 +16,11 @@ class RoomsController {
 
   create = async (req, res, next) => {
     try {
-      const { title } = req.body;
+      if (!req.user || !req.user.userId) {
+        throw new AppError("Utilisateur non authentifié", 401);
+      }
 
+      const { title } = req.body;
       if (!title) {
         throw new AppError(MISSING_REQUIRED_PARAMETER);
       }
@@ -26,18 +29,21 @@ class RoomsController {
 
       const roomExists = await this.rooms.roomExists(normalizedTitle);
 
+
       if (roomExists) {
-        throw new AppError(ROOM_ALREADY_EXISTS);
+        const error = new AppError(ROOM_ALREADY_EXISTS);
+        error.message = "Cette salle existe déjà";
+        error.statusCode = 409;
+        throw error;
       }
-      
       const result = await this.rooms.create(normalizedTitle, req.user.userId);
 
-      return res.status(200).json({
-        message: "Room cree avec succes.",
+      return res.status(201).json({
+        message: "Room créée avec succès.",
         roomId: result.insertedId,
       });
     } catch (error) {
-      return next(error);
+      next(Object.assign(error, { message: error.message }));
     }
   };
 
@@ -194,13 +200,9 @@ class RoomsController {
       if (!title) {
         throw new AppError(MISSING_REQUIRED_PARAMETER);
       }
-
-      const normalizedTitle = title.toLowerCase();
-
-      const exists = await this.rooms.roomExists(normalizedTitle);
+      const exists = await this.rooms.roomExists(title);
 
       return res.status(200).json({
-        message: `La salle avec le titre "${title}" existe déjà.`,
         exists: exists,
       });
     } catch (error) {
diff --git a/server/middleware/errorHandler.js b/server/middleware/errorHandler.js
index 73c3add..ecc6c6c 100644
--- a/server/middleware/errorHandler.js
+++ b/server/middleware/errorHandler.js
@@ -2,17 +2,28 @@ const AppError = require("./AppError");
 const fs = require('fs');
 
 const errorHandler = (error, req, res, _next) => {
-
+    res.setHeader('Cache-Control', 'no-store');
+  
+    // Debug 
+    console.log("Erreur reçue :", {
+      message: error.message,
+      stack: error.stack,
+      constructor: error.constructor.name,
+      proto: Object.getPrototypeOf(error)
+    });
+  
     if (error instanceof AppError) {
-        logError(error);
-        return res.status(error.statusCode).json({
-            error: error.message
-        });
+      return res.status(error.statusCode).json({
+        message: error.message,
+        code: error.statusCode
+      });
     }
-
-    logError(error.stack);
-    return res.status(505).send("Oups! We screwed up big time. 	┻━┻ ︵ヽ(`Д´)ﾉ︵ ┻━┻");
-}
+  
+    return res.status(500).json({
+      message: "Erreur technique",
+      code: 500
+    });
+  };
 
 const logError = (error) => {
     const time = new Date();
diff --git a/server/models/room.js b/server/models/room.js
index 27be617..d3f6a28 100644
--- a/server/models/room.js
+++ b/server/models/room.js
@@ -6,34 +6,38 @@ class Rooms {
     }
 
     async create(title, userId) {
-
-        if (!title || !userId) {
-            throw new Error('Missing required parameter(s)');
+        try {
+            if (!title || !userId) {
+                throw new AppError('Missing required parameter(s)', 400);
+            }
+    
+            await this.db.connect();
+            const conn = this.db.getConnection();
+            const roomsCollection = conn.collection('rooms');
+            const normalizedTitle = title.toLowerCase();
+    
+            const existingRoom = await roomsCollection.findOne({ title: normalizedTitle, userId: userId });
+    
+            if (existingRoom) {
+                throw new AppError('Une salle avec ce nom existe déjà', 409);
+            }
+    
+            const newRoom = {
+                userId: userId,
+                title: title,
+                created_at: new Date()
+            };
+    
+            const result = await roomsCollection.insertOne(newRoom);
+    
+            return result.insertedId;
+    
+        } catch (error) {
+            console.error("Error in create function:", error);
+            throw new AppError(error.message || "Internal Server Error", 500);
         }
-
-        await this.db.connect()
-        const conn = this.db.getConnection();
-
-        const roomsCollection = conn.collection('rooms');
-
-        const normalizedTitle = title.toLowerCase();
-
-        const existingRoom = await roomsCollection.findOne({ title: normalizedTitle, userId: userId });
-
-        if (existingRoom) {
-            throw new Error('Room already exists');
-        }
-
-        const newRoom = {
-            userId: userId,
-            title: title,
-            created_at: new Date()
-        }
-
-        const result = await roomsCollection.insertOne(newRoom);
-
-        return result.insertedId;
     }
+    
 
     async getUserRooms(userId) {
         await this.db.connect()
@@ -101,16 +105,20 @@ class Rooms {
         return true
     }
 
-    async roomExists(title) {
-        await this.db.connect();
-        const conn = this.db.getConnection();
-
-        const roomsCollection = conn.collection('rooms');
-        const normalizedTitle = title.toLowerCase();
-        const existingRoom = await roomsCollection.findOne({ title: normalizedTitle });
-        return existingRoom ? true : false;
+    async roomExists(title) { // Ajouter userId en paramètre
+        try {
+            await this.db.connect();
+            const conn = this.db.getConnection();
+            const existingRoom = await conn.collection('rooms').findOne({ 
+                title: title.toLowerCase()
+            });
+            return !!existingRoom;
+        } catch (error) {
+            throw new AppError("Erreur base de données", 500); // Encapsuler les erreurs
+        }
     }
 
+
     async getRoomById(roomId) {
         await this.db.connect();
         const conn = this.db.getConnection();