diff --git a/tidal_dl_ng/api.py b/tidal_dl_ng/api.py
index e601a6d..0679c80 100644
--- a/tidal_dl_ng/api.py
+++ b/tidal_dl_ng/api.py
@@ -102,5 +102,7 @@ try:
     if respond.status_code == 200:
         content = respond.json()["files"]["tidal-api-key.json"]["content"]
         __API_KEYS__ = json.loads(content)
-except:
+except Exception as e:
+    # TODO: Implement proper logging.
+    print(e)
     pass
diff --git a/tidal_dl_ng/download.py b/tidal_dl_ng/download.py
index 4804147..a84996f 100644
--- a/tidal_dl_ng/download.py
+++ b/tidal_dl_ng/download.py
@@ -29,7 +29,9 @@ from tidal_dl_ng.model.gui_data import ProgressBars
 # TODO: Set appropriate client string and use it for video download.
 # https://github.com/globocom/m3u8#using-different-http-clients
 class RequestsClient:
-    def download(self, uri: str, timeout: int = None, headers: dict | None = None, verify_ssl: bool = True):
+    def download(
+        self, uri: str, timeout: int = REQUESTS_TIMEOUT_SEC, headers: dict | None = None, verify_ssl: bool = True
+    ):
         if not headers:
             headers = {}
 
diff --git a/tidal_dl_ng/gui.py b/tidal_dl_ng/gui.py
index 064826b..5c5061f 100644
--- a/tidal_dl_ng/gui.py
+++ b/tidal_dl_ng/gui.py
@@ -409,7 +409,7 @@ class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
         )
         progress: Progress = Progress()
 
-        if isinstance(media, (Track, Video)):
+        if isinstance(media, Track | Video):
             if isinstance(media, Track):
                 file_template: str = self.settings.data.format_track
             elif isinstance(media, Video):
@@ -428,7 +428,7 @@ class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
                 logger_gui.info(f"Download successful: {download_path_file}")
             else:
                 logger_gui.info(f"Download skipped (file exists): {download_path_file}")
-        elif isinstance(media, (Album, Playlist, Mix)):
+        elif isinstance(media, Album | Playlist | Mix):
             file_template: str | bool = False
 
             if isinstance(media, Album):
diff --git a/tidal_dl_ng/helper/decorator.py b/tidal_dl_ng/helper/decorator.py
index 545f73b..ba0f417 100644
--- a/tidal_dl_ng/helper/decorator.py
+++ b/tidal_dl_ng/helper/decorator.py
@@ -1,3 +1,6 @@
+from typing import ClassVar
+
+
 class SingletonMeta(type):
     """
     The Singleton class can be implemented in different ways in Python. Some
@@ -5,7 +8,7 @@ class SingletonMeta(type):
     metaclass because it is best suited for this purpose.
     """
 
-    _instances = {}
+    _instances: ClassVar[dict] = {}
 
     def __call__(cls, *args, **kwargs):
         """
diff --git a/tidal_dl_ng/helper/path.py b/tidal_dl_ng/helper/path.py
index 31e9a88..3061160 100644
--- a/tidal_dl_ng/helper/path.py
+++ b/tidal_dl_ng/helper/path.py
@@ -111,7 +111,7 @@ def get_fn_format(media: Track | Album | Playlist | UserPlaylist | Video | Mix)
         result = format_str_track
     elif isinstance(media, Album):
         result = format_str_album
-    elif isinstance(media, (Playlist, UserPlaylist)):
+    elif isinstance(media, Playlist | UserPlaylist):
         result = format_str_playlist
     elif isinstance(media, Mix):
         result = format_str_mix
@@ -128,8 +128,9 @@ def length_max_name_file() -> int:
     try:
         if system in ["Darwin", "Linux"]:
             result: int = os.pathconf("/", "PC_NAME_MAX")
-    except Exception:
-        pass
+    except Exception as e:
+        # TODO: Implement propper logging.
+        print(e)
 
     return result
 
@@ -141,8 +142,9 @@ def length_max_name_path() -> int:
     try:
         if system in ["Darwin", "Linux"]:
             result: int = os.pathconf("/", "PC_PATH_MAX")
-    except Exception:
-        pass
+    except Exception as e:
+        # TODO: Implement propper logging.
+        print(e)
 
     return result