diff --git a/.github/workflows/examples.yml b/.github/workflows/examples.yml
index 1dd8fc8..617d321 100644
--- a/.github/workflows/examples.yml
+++ b/.github/workflows/examples.yml
@@ -15,15 +15,15 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python_version: [3.9]
+        python_version: ["3.10"]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         submodules: 'recursive'
 
     - name: Set up Python
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python_version }}
 
diff --git a/aw_client/classes.py b/aw_client/classes.py
index 3f07cae..45038cc 100644
--- a/aw_client/classes.py
+++ b/aw_client/classes.py
@@ -80,5 +80,10 @@ def get_classes() -> List[Tuple[List[str], dict]]:
             "Failed to get classes from server, using default classes as fallback"
         )
         return default_classes
+    if not classes:
+        logger.warning(
+            "Classes setting is empty/unset, using default classes as fallback"
+        )
+        return default_classes
     # map into list of tuples
     return [(v["name"], v["rule"]) for v in classes]
diff --git a/aw_client/cli.py b/aw_client/cli.py
index c4e3000..c1215ed 100755
--- a/aw_client/cli.py
+++ b/aw_client/cli.py
@@ -103,9 +103,11 @@ def events(obj: _Context, bucket_id: str):
 @click.option("--json", "_json", is_flag=True)
 @click.option("--start", default=now - td1day, type=click.DateTime())
 @click.option("--stop", default=now + td1yr, type=click.DateTime())
-@click.option("--timezone",
-              help="Time zone for start and stop options."
-              " Must be a valid IANA identifier like e.g. 'Europe/Warsaw'.")
+@click.option(
+    "--timezone",
+    help="Time zone for start and stop options."
+    " Must be a valid IANA identifier like e.g. 'Europe/Warsaw'.",
+)
 @click.pass_obj
 def query(
     obj: _Context,
diff --git a/examples/suggest_categories.py b/examples/suggest_categories.py
index 4e37999..d6fbf46 100644
--- a/examples/suggest_categories.py
+++ b/examples/suggest_categories.py
@@ -13,7 +13,6 @@
 import aw_client
 from aw_client import queries
 
-
 # set up client
 awc = aw_client.ActivityWatchClient("test")
 
diff --git a/examples/working_hours.py b/examples/working_hours.py
index df4e37c..a6d10c5 100644
--- a/examples/working_hours.py
+++ b/examples/working_hours.py
@@ -19,7 +19,6 @@
 from aw_transform import flood
 from tabulate import tabulate
 
-
 OUTPUT_HTML = os.environ.get("OUTPUT_HTML", "").lower() == "true"
 
 td1d = timedelta(days=1)