diff --git a/src/app.ts b/src/app.ts
index 65591e9..a863a4d 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -43,7 +43,7 @@ try {
 	app.use("/auth", AuthRouter);
 	app.use("/catalog", CatalogRouter);
 	app.use("/rent", RentRouter);
-	logger.info("Routers loaded !\n");
+	logger.info("Routers loaded !");
 } catch (err) {
 	logger.error(err);
 	throw null;
@@ -53,9 +53,9 @@ try {
 	app.listen(process.env["APP_PORT"]);
 	logger.info(
 		`Server is running !\n >> Memory total: ${
-			process.memoryUsage().rss / 1_000_000
-		} Mio\n >> Memory heap usage: ${
-			process.memoryUsage().heapUsed / 1_000_000
+			Math.round(process.memoryUsage().rss / 1_000_000)
+		} Mio\n >> Memory heap: ${
+			Math.round(process.memoryUsage().heapUsed / 1_000_000)
 		} Mio\n`,
 	);
 } catch (error) {
diff --git a/src/controllers/auth.controller.ts b/src/controllers/auth.controller.ts
index 5b2be59..89cb6a3 100644
--- a/src/controllers/auth.controller.ts
+++ b/src/controllers/auth.controller.ts
@@ -6,6 +6,7 @@ import UserService from "@services/user.service";
 import { isEmail } from "@utils/validators/email";
 import type { Request, Response } from "express";
 import { Logger } from "tslog";
+import {isDebugMode} from "@utils/debugState";
 
 const logger = new Logger({
 	name: "AuthController",
@@ -61,8 +62,8 @@ async function registerUser(req: Request, res: Response): Promise<unknown> {
 			message: "GDPR not accepted.",
 		});
 	}
-	if (RegisterServiceResult.error === "exist") {
-		logger.warn(`The user already exists (${req.ip})`);
+	if (typeof RegisterServiceResult !== 'string' && RegisterServiceResult.error === 5) {
+		logger.warn(`The user already exists (${sanitizeData.email})`);
 		return res.type("application/json").status(400).json({
 			error: RegisterServiceResult.error,
 			message: "The user already exists.",
@@ -70,8 +71,8 @@ async function registerUser(req: Request, res: Response): Promise<unknown> {
 	}
 
 	// SUCCESS
-	logger.info(`User registered successfully (${sanitizeData.username})`);
-	return res.type("application/json").status(201).json(RegisterServiceResult);
+	//logger.info(`User registered successfully (${sanitizeData.username})`);
+	return res.type("application/json").status(201).json({token:RegisterServiceResult});
 }
 
 /**
@@ -393,7 +394,7 @@ async function getSelf(req: Request, res: Response) {
 	});
 }
 
-logger.debug("\nController loaded.");
+if (isDebugMode()) logger.debug("\nController loaded.");
 
 const AuthController = {
 	register: registerUser,
diff --git a/src/controllers/brand.controller.ts b/src/controllers/brand.controller.ts
index c99a4e4..ea32eb9 100644
--- a/src/controllers/brand.controller.ts
+++ b/src/controllers/brand.controller.ts
@@ -3,6 +3,7 @@ import { Logger } from "tslog";
 
 import type IDbBrand from "@interfaces/database/IDbBrand";
 import BrandService from "@services/brand.service";
+import {isDebugMode} from "@utils/debugState";
 //import {body} from "express-validator";
 
 const logger = new Logger({
@@ -171,7 +172,7 @@ async function deleteBrand(req: Request, res: Response): Promise<Response> {
 
 //TODO get models of the brand
 
-logger.debug("\nController loaded.");
+if (isDebugMode()) logger.debug("\nController loaded.");
 
 const BrandController = {
 	create: createBrand,
diff --git a/src/controllers/category.controller.ts b/src/controllers/category.controller.ts
index 7a500b3..0d18547 100644
--- a/src/controllers/category.controller.ts
+++ b/src/controllers/category.controller.ts
@@ -2,6 +2,7 @@ import type IDbCategory from "@interfaces/database/IDbCategory";
 import CategoryService from "@services/category.service";
 import type { Request, Response } from "express";
 import { Logger } from "tslog";
+import {isDebugMode} from "@utils/debugState";
 //import {validationResult} from "express-validator";
 
 const logger = new Logger({
@@ -177,7 +178,7 @@ async function getBySlugCategory(
 	});
 }
 
-logger.debug("\nController loaded.");
+if (isDebugMode()) logger.debug("\nController loaded.");
 
 const CategoryController = {
 	create: createCategory,
diff --git a/src/controllers/model.controller.ts b/src/controllers/model.controller.ts
index e8d141d..8b8218b 100644
--- a/src/controllers/model.controller.ts
+++ b/src/controllers/model.controller.ts
@@ -3,6 +3,7 @@ import CategoryService from "@services/category.service";
 import ModelService from "@services/model.service";
 import type { Request, Response } from "express";
 import { Logger } from "tslog";
+import {isDebugMode} from "@utils/debugState";
 //import {validationResult} from "express-validator";
 
 const logger = new Logger({
@@ -131,7 +132,7 @@ async function deleteModel(req: Request, res: Response): Promise<Response> {
 
 //TODO get model with vehicle available.
 
-logger.debug("\nController loaded.");
+if (isDebugMode()) logger.debug("\nController loaded.");
 
 const ModelController = {
 	create: createModel,
diff --git a/src/services/brand.service.ts b/src/services/brand.service.ts
index 3a012b8..cb9026e 100644
--- a/src/services/brand.service.ts
+++ b/src/services/brand.service.ts
@@ -2,6 +2,7 @@ import type IDbBrand from "@interfaces/database/IDbBrand";
 import MysqlService from "@services/mysql.service";
 import { Logger } from "tslog";
 import { v4 as uuidv4 } from "uuid";
+import {isDebugMode} from "@utils/debugState";
 
 const DbHandler = new MysqlService.Handler("BrandService");
 const logger = new Logger({
@@ -168,7 +169,7 @@ async function deleteBrand(brandId: string): Promise<boolean> {
 	return true;
 }
 
-logger.debug("\nService loaded.");
+if (isDebugMode()) logger.debug("\nService loaded.");
 
 const BrandService = {
 	create: createBrand,
diff --git a/src/services/category.service.ts b/src/services/category.service.ts
index 02fe10c..1a1fda1 100644
--- a/src/services/category.service.ts
+++ b/src/services/category.service.ts
@@ -2,6 +2,7 @@ import type { IDbCategory } from "@interfaces/database/IDbCategory";
 import MysqlService from "@services/mysql.service";
 import { Logger } from "tslog";
 import { v4 as uuidv4 } from "uuid";
+import {isDebugMode} from "@utils/debugState";
 
 const DbHandler = new MysqlService.Handler("CategoryService");
 const logger = new Logger({
@@ -127,7 +128,7 @@ async function deleteCategory(id: string): Promise<unknown> {
 	}
 }
 
-logger.debug("\nService loaded.");
+if (isDebugMode()) logger.debug("\nService loaded.");
 
 const CategoryService = {
 	create: createCategory,
diff --git a/src/services/jwt.service.ts b/src/services/jwt.service.ts
index c1355ef..54a0850 100644
--- a/src/services/jwt.service.ts
+++ b/src/services/jwt.service.ts
@@ -5,6 +5,7 @@ import {
 	jwtVerify,
 } from "jose";
 import { Logger } from "tslog";
+import {isDebugMode} from "@utils/debugState";
 
 const logger = new Logger({
 	name: "JwtService",
@@ -64,7 +65,7 @@ async function JwtSignService(
 		.sign(new TextEncoder().encode(`${process.env["JWT_SECRET"]}`));
 }
 
-logger.debug("\nService loaded.");
+if (isDebugMode()) logger.debug("\nService loaded.");
 
 const JwtService = {
 	verify: JwtVerifyService,
diff --git a/src/services/model.service.ts b/src/services/model.service.ts
index 1bfbd03..c6b8d53 100644
--- a/src/services/model.service.ts
+++ b/src/services/model.service.ts
@@ -2,6 +2,7 @@ import type IDbModel from "@interfaces/database/IDbModel";
 import MysqlService from "@services/mysql.service";
 import { Logger } from "tslog";
 import { v4 as uuidv4 } from "uuid";
+import {isDebugMode} from "@utils/debugState";
 
 const DbHandler = new MysqlService.Handler("ModelService");
 const logger = new Logger({
@@ -135,7 +136,7 @@ async function getAllModels(): Promise<IDbModel[] | null> {
 	}
 }
 
-logger.debug("\nService loaded.");
+if (isDebugMode()) logger.debug("\nService loaded.");
 
 /**
  * ModelService is responsible for managing models.
diff --git a/src/services/mysql.service.ts b/src/services/mysql.service.ts
index aa6e45c..d8dd2d2 100644
--- a/src/services/mysql.service.ts
+++ b/src/services/mysql.service.ts
@@ -12,7 +12,7 @@ import type { IDbVehicle } from "@interfaces/database/IDbVehicle";
 import type { IUserUpdate } from "@interfaces/services/IUserUpdate";
 import mysql, { type Connection, type ConnectionOptions } from "mysql2";
 import { Logger } from "tslog";
-import { v4 } from "uuid";
+import {isDebugMode} from "@utils/debugState";
 
 const access: ConnectionOptions = {
 	host: `${process.env["MYSQL_HOST"]}`,
@@ -35,10 +35,10 @@ class MysqlHandler {
 		this.Connection = mysql.createConnection(access);
 		this.Connection.connect((err) => {
 			if (err) {
-				this.Logger.error(`Error connecting to MySQL: ${err}`);
+				this.Logger.error(`\n\n> Error connecting to MySQL: \n${err}\n`);
 				process.exit(1);
 			}
-			this.Logger.info(
+			if (isDebugMode()) this.Logger.debug(
 				`\n\n> Connected to MySQL database (${access.database})\n`,
 			);
 		});
@@ -51,7 +51,7 @@ class MysqlHandler {
 		return new Promise((resolve, reject) => {
 			this.Connection.query(queryString, (err, results) => {
 				if (err) {
-					this.Logger.error(`Error executing query: ${err}`);
+					this.Logger.error(`\n\n> Error executing query: \n${err}\n`);
 					reject(err);
 				} else {
 					resolve(results);
@@ -82,12 +82,12 @@ class MysqlHandler {
 					(key: string) => `${key}`,
 				);
 				const values = Object.values(data.values).map((val) => val);
-				this.Logger.debug(
+				if (isDebugMode()) this.Logger.debug(
 					`\n\n>-> Factorized ${_sqlQueryKeys.length} keys for a prepare Query.\n>-> Action: ${data.actionName}\n`,
 				);
 				const sqlQueryKeys = _sqlQueryKeys.join(", ");
 				if (_id && _id.length > 2) {
-					this.Logger.trace(`Id post-pushed in factorized data`);
+					if (isDebugMode()) this.Logger.trace(`\n\n> Id post-pushed in factorized data.\n   ${_id}`);
 					values.push(_id);
 				}
 
@@ -176,19 +176,6 @@ const MySqlService = {
 				if (!data.id) return reject("Id is undefined");
 				if (data.id.length !== 36) return reject("Id invalid");
 
-				// const _values = [
-				// 	data.id,
-				// 	data.username,
-				// 	data.firstname,
-				// 	data.lastname,
-				// 	data.dob,
-				// 	data.email,
-				// 	data.is_mail_verified,
-				// 	data.is_admin,
-				// 	data.gdpr,
-				// 	data.hash,
-				// ];
-
 				handler
 					.factorize({
 						values: data,
diff --git a/src/services/user.service.ts b/src/services/user.service.ts
index 6da1ce6..dbd44bb 100644
--- a/src/services/user.service.ts
+++ b/src/services/user.service.ts
@@ -7,6 +7,7 @@ import JwtService from "@services/jwt.service";
 import MySqlService from "@services/mysql.service";
 import { Logger } from "tslog";
 import { v4 } from "uuid";
+import {isDebugMode} from "@utils/debugState";
 
 const logger = new Logger({
 	name: "UserService",
@@ -63,14 +64,19 @@ async function getUserFromIdService(id: string): Promise<IDbUser | ISError> {
 			};
 		}
 		const dbUser = await MySqlService.User.getById(DbHandler, id);
-		if (dbUser === undefined) {
+		if (dbUser.length === 0) {
 			logger.info(`User not found (${id})`);
 			return {
 				error: ErrorType.NotFound,
 				message: "The user was not found.",
 			};
 		}
-		return dbUser;
+		const firstUser = dbUser[0];
+		if (firstUser) return firstUser;
+		return {
+      error: ErrorType.ServiceError,
+      message: "No user found.",
+    };
 	} catch (err) {
 		return {
 			error: ErrorType.DatabaseError,
@@ -123,13 +129,7 @@ async function register(inputData: IReqRegister): Promise<ISError | string> {
 		const dbUserIfExist: IDbUser | ISError = await getUserByEmail(
 			inputData.email,
 		);
-		if ("error" in dbUserIfExist) {
-			return {
-				error: dbUserIfExist.error,
-				message: dbUserIfExist.message,
-			};
-		}
-		if (dbUserIfExist.id) {
+		if ("username" in dbUserIfExist) {
 			logger.info(
 				`\n\n> User already exist for email "${inputData.email}".\n(${dbUserIfExist.username}::${dbUserIfExist.id})\n`,
 			);
@@ -152,7 +152,7 @@ async function register(inputData: IReqRegister): Promise<ISError | string> {
 			is_admin: false,
 			is_email_verified: false,
 		});
-		if ("error" in NewUser || NewUser.affectedRows === 0) {
+		if ("error" in NewUser && NewUser.affectedRows === 0) {
 			return {
 				error: ErrorType.DatabaseError,
 				message: "Error when inserting user in database.",
@@ -326,7 +326,7 @@ async function deleteUserService(targetId) {
 	}
 }
 
-logger.debug("\nService loaded.");
+if (isDebugMode()) logger.debug("\nService loaded.");
 
 const UserService = {
 	register: register,
diff --git a/src/validators/AdminGuard.ts b/src/validators/AdminGuard.ts
index 6e5b84d..bcb90cd 100644
--- a/src/validators/AdminGuard.ts
+++ b/src/validators/AdminGuard.ts
@@ -33,7 +33,7 @@ async function AdminGuard(req: Request, res: Response, next: NextFunction) {
 
 	const token = await JwtService.verify(bearerToken);
 
-	if (token) {
+	if (token && token.sub) {
 		// @ts-ignore
 		const isSourceAdmin = await MysqlService.User.getAdminStateForId(
 			DbHandler,