diff --git a/km3io/offline.py b/km3io/offline.py
index 4ef4470c8a9e845ea778ec18dd2eabd43d19b8d6..3a04e793af707062eb24364410e86b99c865403f 100644
--- a/km3io/offline.py
+++ b/km3io/offline.py
@@ -137,6 +137,8 @@ class Usr:
                     basketcache=BASKET_CACHE)[0]
             ]
         except (KeyError, IndexError):  # e.g. old aanet files
+            print("The `usr` fields could not be parsed for the '{}' branch."
+                  .format(name))
             self._usr_names = []
         else:
             self._usr_idx_lookup = {
diff --git a/tests/test_offline.py b/tests/test_offline.py
index 1d5229a1df8dbf66666c7523dee06ad057bcf455..0001a252f2dec6ff66596cf551f3d8cc397dce06 100644
--- a/tests/test_offline.py
+++ b/tests/test_offline.py
@@ -173,53 +173,20 @@ class TestOfflineHits(unittest.TestCase):
 class TestOfflineTracks(unittest.TestCase):
     def setUp(self):
         self.tracks = OFFLINE_FILE.events.tracks
-        self.r_mc = OFFLINE_NUMUCC
-        self.Nevents = 10
+        self.tracks_numucc = OFFLINE_NUMUCC
+        self.n_events = 10
+
+    def test_attributes_available(self):
+        for key in self.tracks._keymap.keys():
+            getattr(self.tracks, key)
 
-    @unittest.skip
     def test_item_selection(self):
         self.assertListEqual(list(self.tracks[0].dir_z[:2]),
                              [-0.872885221293917, -0.872885221293917])
 
-    @unittest.skip
-    def test_IndexError(self):
-        # test handling IndexError with empty lists/arrays
-        self.assertEqual(len(OfflineTracks(['whatever'], [])), 0)
-
-    @unittest.skip
     def test_repr(self):
         assert " 10 " in repr(self.tracks)
 
-    @unittest.skip
-    def test_str(self):
-        assert str(self.tracks).endswith(" 10")
-
-    @unittest.skip
-    def test_reading_tracks_dir_z(self):
-        dir_z = self.tracks.dir_z
-        tracks_dir_z = {0: 56, 1: 55, 8: 54}
-
-        for track_id, n_dir in tracks_dir_z.items():
-            self.assertEqual(n_dir, len(dir_z[track_id]))
-
-        # check that there are 10 arrays of tracks.dir_z info
-        self.assertEqual(len(dir_z), self.Nevents)
-
-    @unittest.skip
-    def test_reading_mc_tracks_dir_z(self):
-        dir_z = self.r_mc.mc_tracks.dir_z
-        tracks_dir_z = {0: 11, 1: 25, 8: 13}
-
-        for track_id, n_dir in tracks_dir_z.items():
-            self.assertEqual(n_dir, len(dir_z[track_id]))
-
-        # check that there are 10 arrays of tracks.dir_z info
-        self.assertEqual(len(dir_z), self.Nevents)
-
-        self.assertListEqual([0.230189, 0.230189, 0.218663],
-                             list(dir_z[0][:3]))
-
-    @unittest.skip
     def test_slicing(self):
         tracks = self.tracks
         assert 10 == len(tracks)