diff --git a/language_label_mapper.py b/language_label_mapper.py
index cda4eba..aeaf1a0 100644
--- a/language_label_mapper.py
+++ b/language_label_mapper.py
@@ -19,7 +19,7 @@ def translate(to_translate, lang):
         for index, label_info in to_translate.items():
             label = label_info.get("label")
             to_translate[index]["label"] = config.get(label).data
-        return to_translate, None
+        return to_translate, []
     except Exception as e:
         error_message = f"Error translating labels: {e}"
         print(error_message)
diff --git a/main.py b/main.py
index 7266608..b0be64d 100644
--- a/main.py
+++ b/main.py
@@ -95,7 +95,7 @@ def upload_file():
             'isCat': False if not predictions else True,
             **({'predictions': predictions} if predictions is not None else {})
         }
-        if error_messages is not None and predictions is None:
+        if len(error_messages) > 1:
             results['errors'].append(error_messages)
 
     # Send response with 200 (Success)
diff --git a/validator.py b/validator.py
index b6afca0..8aa7ec5 100644
--- a/validator.py
+++ b/validator.py
@@ -25,7 +25,7 @@ def validate(request):
 
         # Case 3 -> if some of the images has wrong extension
         for img in images:
-            if imghdr.what(img) not in allowed_extensions:
+            if not img.filename.lower().endswith(('.png', '.jpg', '.jpeg')):
                 raise ValueError(f"Given file '{img.filename}' has no allowed extension. "
                                  f"Allowed extensions: {allowed_extensions}.")
     except Exception as e: