diff --git a/AnkiConnect.py b/AnkiConnect.py
index 6976928..7dca7c1 100644
--- a/AnkiConnect.py
+++ b/AnkiConnect.py
@@ -89,11 +89,11 @@ def makeStr(data):
 def download(url):
     try:
         resp = web.urlopen(url, timeout=URL_TIMEOUT)
-    except web.URLError:
-        return None
+    except web.URLError as e:
+        raise Exception('A urlError has occurred for url ' + url + '. Error messages was: ' + e.message)
 
     if resp.code != 200:
-        return None
+        raise Exception('Return code for url request' + url + 'was not 200. Error code: ' + resp.code)
 
     return resp.read()
 
@@ -337,7 +337,9 @@ class AnkiNoteParams:
             type(self.fields) == dict and verifyStringList(list(self.fields.keys())) and verifyStringList(list(self.fields.values())) and
             type(self.tags) == list and verifyStringList(self.tags)
         )
-
+    
+    def __str__(self):
+        return 'DeckName: ' + self.deckName + '. ModelName: ' + self.modelName + '. Fields: ' + str(self.fields) + '. Tags: ' + str(self.tags) + '.'
 
 #
 # AnkiBridge
@@ -352,7 +354,7 @@ class AnkiBridge:
     def retrieveMediaFile(self, filename):
         # based on writeData from anki/media.py
         filename = os.path.basename(filename)
-        filename = normalize("NFC", filename)
+        filename = normalize('NFC', filename)
         filename = self.media().stripIllegal(filename)
 
         path = os.path.join(self.media().dir(), filename)
@@ -370,11 +372,11 @@ class AnkiBridge:
     def addNote(self, params):
         collection = self.collection()
         if collection is None:
-            return
+            raise Exception('Collection was not found.')
 
         note = self.createNote(params)
         if note is None:
-            return
+            raise Exception('Failed to create note from params: ' + str(params))
 
         if params.audio is not None and len(params.audio.fields) > 0:
             data = download(params.audio.url)
@@ -405,15 +407,15 @@ class AnkiBridge:
     def createNote(self, params):
         collection = self.collection()
         if collection is None:
-            return
+            raise Exception('Collection was not found.')
 
         model = collection.models.byName(params.modelName)
         if model is None:
-            return
+            raise Exception('Model was not found for model: ' + params.modelName)
 
         deck = collection.decks.byName(params.deckName)
         if deck is None:
-            return
+            raise Exception('Deck was not found for deck: ' + params.deckName)
 
         note = anki.notes.Note(collection, model)
         note.model()['did'] = deck['id']
@@ -423,17 +425,23 @@ class AnkiBridge:
             if name in note:
                 note[name] = value
 
-        if not note.dupeOrEmpty():
+        # Returns 1 if empty. 2 if duplicate. Otherwise returns False
+        duplicateOrEmpty = note.dupeOrEmpty()
+        if duplicateOrEmpty == 1:
+            raise Exception('Note was empty. Param were: ' + str(params))
+        elif duplicateOrEmpty == 2:
+            raise Exception('Note is duplicate of existing note. Params were: ' + str(params))
+        elif duplicateOrEmpty == False:
             return note
 
     def updateNoteFields(self, params):
         collection = self.collection()
         if collection is None:
-            return
+            raise Exception('Collection was not found.')
 
         note = collection.getNote(params['id'])
         if note is None:
-            raise Exception("Failed to get note:{}".format(params['id']))
+            raise Exception('Failed to get note:{}'.format(params['id']))
         for name, value in params['fields'].items():
             if name in note:
                 note[name] = value
@@ -606,7 +614,7 @@ class AnkiBridge:
                     for match in matches:
                         # remove braces and modifiers
                         match = re.sub(r'[{}]', '', match)
-                        match = match.split(":")[-1]
+                        match = match.split(':')[-1]
 
                         # for the answer side, ignore fields present on the question side + the FrontSide field
                         if match == 'FrontSide' or side == 'afmt' and match in fields[0]:
@@ -744,7 +752,7 @@ class AnkiBridge:
                 })
             except TypeError as e:
                 # Anki will give a TypeError if the card ID does not exist.
-                # Best behavior is probably to add an "empty card" to the
+                # Best behavior is probably to add an 'empty card' to the
                 # returned result, so that the items of the input and return
                 # lists correspond.
                 result.append({})
@@ -770,11 +778,11 @@ class AnkiBridge:
                     'fields': fields,
                     'modelName': model['name'],
                     'cards': self.collection().db.list(
-                        "select id from cards where nid = ? order by ord", note.id)
+                        'select id from cards where nid = ? order by ord', note.id)
                 })
             except TypeError as e:
                 # Anki will give a TypeError if the note ID does not exist.
-                # Best behavior is probably to add an "empty card" to the
+                # Best behavior is probably to add an 'empty card' to the
                 # returned result, so that the items of the input and return
                 # lists correspond.
                 result.append({})
@@ -856,7 +864,7 @@ class AnkiBridge:
 
     def guiCurrentCard(self):
         if not self.guiReviewActive():
-            return
+            raise Exception('Gui review is not currently active.')
 
         reviewer = self.reviewer()
         card = reviewer.card
@@ -1112,10 +1120,13 @@ class AnkiConnect:
     def addNotes(self, notes):
         results = []
         for note in notes:
-            params = AnkiNoteParams(note)
-            if params.validate():
-                results.append(self.anki.addNote(params))
-            else:
+            try:
+                params = AnkiNoteParams(note)
+                if params.validate():
+                    results.append(self.anki.addNote(params))
+                else:
+                    results.append(None)
+            except Exception:
                 results.append(None)
 
         return results