diff --git a/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameController.java b/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameController.java
index 0e77237..ec9449c 100644
--- a/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameController.java
+++ b/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameController.java
@@ -29,11 +29,11 @@ public class BlackJackGameController {
     }
 
     @GetMapping("/blackjack/{id}")
-    public ResponseEntity<Object> getGame(@PathVariable Long id, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> getGame(@PathVariable Long id) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
@@ -46,11 +46,11 @@ public class BlackJackGameController {
     }
 
     @PostMapping("/blackjack/{id}/hit")
-    public ResponseEntity<Object> hit(@PathVariable Long id, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> hit(@PathVariable Long id) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
@@ -63,11 +63,11 @@ public class BlackJackGameController {
     }
 
     @PostMapping("/blackjack/{id}/stand")
-    public ResponseEntity<Object> stand(@PathVariable Long id, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> stand(@PathVariable Long id) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
@@ -80,11 +80,11 @@ public class BlackJackGameController {
     }
 
     @PostMapping("/blackjack/{id}/doubleDown")
-    public ResponseEntity<Object> doubleDown(@PathVariable Long id, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> doubleDown(@PathVariable Long id) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
@@ -97,11 +97,11 @@ public class BlackJackGameController {
     }
 
     @PostMapping("/blackjack/{id}/split")
-    public ResponseEntity<Object> split(@PathVariable Long id, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> split(@PathVariable Long id) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
@@ -114,11 +114,11 @@ public class BlackJackGameController {
     }
 
     @PostMapping("/blackjack/start")
-    public ResponseEntity<Object> createBlackJackGame(@RequestBody @Valid BetDto betDto, @RequestHeader("Authorization") String token) {
+    public ResponseEntity<Object> createBlackJackGame(@RequestBody @Valid BetDto betDto) {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
diff --git a/backend/src/main/java/de/szut/casino/config/WebConfig.java b/backend/src/main/java/de/szut/casino/config/WebConfig.java
index 9258349..bb11293 100644
--- a/backend/src/main/java/de/szut/casino/config/WebConfig.java
+++ b/backend/src/main/java/de/szut/casino/config/WebConfig.java
@@ -27,4 +27,4 @@ public class WebConfig {
             }
         };
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/exceptionHandling/exceptions/UserNotFoundException.java b/backend/src/main/java/de/szut/casino/exceptionHandling/exceptions/UserNotFoundException.java
index 6e281db..d843af7 100644
--- a/backend/src/main/java/de/szut/casino/exceptionHandling/exceptions/UserNotFoundException.java
+++ b/backend/src/main/java/de/szut/casino/exceptionHandling/exceptions/UserNotFoundException.java
@@ -5,7 +5,7 @@ import org.springframework.web.bind.annotation.ResponseStatus;
 
 @ResponseStatus(value = HttpStatus.NOT_FOUND)
 public class UserNotFoundException extends RuntimeException {
-    public UserNotFoundException(String message) {
-        super(message);
+    public UserNotFoundException() {
+        super("User not found");
     }
 }
diff --git a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxController.java b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxController.java
index 1b58056..cd9e9f0 100644
--- a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxController.java
+++ b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxController.java
@@ -17,7 +17,7 @@ public class LootBoxController {
     private final UserService userService;
     private final LootBoxService lootBoxService;
 
-    public LootBoxController(LootBoxRepository lootBoxRepository, UserRepository userRepository, UserService userService, LootBoxService lootBoxService) {
+    public LootBoxController(LootBoxRepository lootBoxRepository, UserService userService, LootBoxService lootBoxService) {
         this.lootBoxRepository = lootBoxRepository;
         this.userService = userService;
         this.lootBoxService = lootBoxService;
@@ -39,7 +39,7 @@ public class LootBoxController {
 
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();
diff --git a/backend/src/main/java/de/szut/casino/security/AuthController.java b/backend/src/main/java/de/szut/casino/security/AuthController.java
index f299ef4..57f7abe 100644
--- a/backend/src/main/java/de/szut/casino/security/AuthController.java
+++ b/backend/src/main/java/de/szut/casino/security/AuthController.java
@@ -28,4 +28,4 @@ public class AuthController {
         GetUserDto response = authService.register(signUpRequest);
         return ResponseEntity.ok(response);
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/CorsFilter.java b/backend/src/main/java/de/szut/casino/security/CorsFilter.java
index cf0a368..616cafe 100644
--- a/backend/src/main/java/de/szut/casino/security/CorsFilter.java
+++ b/backend/src/main/java/de/szut/casino/security/CorsFilter.java
@@ -39,4 +39,4 @@ public class CorsFilter implements Filter {
         
         chain.doFilter(req, res);
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/dto/AuthResponseDto.java b/backend/src/main/java/de/szut/casino/security/dto/AuthResponseDto.java
index bf2c51c..0dd03dd 100644
--- a/backend/src/main/java/de/szut/casino/security/dto/AuthResponseDto.java
+++ b/backend/src/main/java/de/szut/casino/security/dto/AuthResponseDto.java
@@ -16,4 +16,4 @@ public class AuthResponseDto {
     public AuthResponseDto(String token) {
         this.token = token;
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/dto/LoginRequestDto.java b/backend/src/main/java/de/szut/casino/security/dto/LoginRequestDto.java
index f07396c..ace3508 100644
--- a/backend/src/main/java/de/szut/casino/security/dto/LoginRequestDto.java
+++ b/backend/src/main/java/de/szut/casino/security/dto/LoginRequestDto.java
@@ -16,4 +16,4 @@ public class LoginRequestDto {
     
     @NotBlank(message = "Password is required")
     private String password;
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/jwt/JwtAuthenticationFilter.java b/backend/src/main/java/de/szut/casino/security/jwt/JwtAuthenticationFilter.java
index a729b36..502ba0a 100644
--- a/backend/src/main/java/de/szut/casino/security/jwt/JwtAuthenticationFilter.java
+++ b/backend/src/main/java/de/szut/casino/security/jwt/JwtAuthenticationFilter.java
@@ -61,4 +61,4 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
 
         return null;
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/jwt/JwtUtils.java b/backend/src/main/java/de/szut/casino/security/jwt/JwtUtils.java
index fac25a1..3c5ef86 100644
--- a/backend/src/main/java/de/szut/casino/security/jwt/JwtUtils.java
+++ b/backend/src/main/java/de/szut/casino/security/jwt/JwtUtils.java
@@ -80,4 +80,4 @@ public class JwtUtils {
         final String username = extractUsername(token);
         return (username.equals(userDetails.getUsername()) && !isTokenExpired(token));
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/service/AuthService.java b/backend/src/main/java/de/szut/casino/security/service/AuthService.java
index d25c953..88687ba 100644
--- a/backend/src/main/java/de/szut/casino/security/service/AuthService.java
+++ b/backend/src/main/java/de/szut/casino/security/service/AuthService.java
@@ -47,4 +47,4 @@ public class AuthService {
                 user.getBalance()
         );
     }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/security/service/UserDetailsServiceImpl.java b/backend/src/main/java/de/szut/casino/security/service/UserDetailsServiceImpl.java
index bae4adf..8653fee 100644
--- a/backend/src/main/java/de/szut/casino/security/service/UserDetailsServiceImpl.java
+++ b/backend/src/main/java/de/szut/casino/security/service/UserDetailsServiceImpl.java
@@ -34,15 +34,4 @@ public class UserDetailsServiceImpl implements UserDetailsService {
                 userEntity.getPassword(), 
                 new ArrayList<>());
     }
-    
-    public UserEntity getUserByUsernameOrEmail(String usernameOrEmail) {
-        Optional<UserEntity> user = userRepository.findByUsername(usernameOrEmail);
-        
-        if (user.isEmpty()) {
-            user = userRepository.findByEmail(usernameOrEmail);
-        }
-        
-        return user.orElseThrow(() -> 
-                new UserNotFoundException("User not found with username or email: " + usernameOrEmail));
-    }
-}
\ No newline at end of file
+}
diff --git a/backend/src/main/java/de/szut/casino/slots/SlotController.java b/backend/src/main/java/de/szut/casino/slots/SlotController.java
index 030e9d8..f22bf65 100644
--- a/backend/src/main/java/de/szut/casino/slots/SlotController.java
+++ b/backend/src/main/java/de/szut/casino/slots/SlotController.java
@@ -33,7 +33,7 @@ public class SlotController {
         Optional<UserEntity> optionalUser = userService.getCurrentUser();
 
         if (optionalUser.isEmpty()) {
-            throw new UserNotFoundException("User not found");
+            throw new UserNotFoundException();
         }
 
         UserEntity user = optionalUser.get();