diff --git a/plexapi/server.py b/plexapi/server.py
index e2b4d631..a55582bf 100644
--- a/plexapi/server.py
+++ b/plexapi/server.py
@@ -438,7 +438,7 @@ class PlexServer(PlexObject):
         log.debug('%s %s', method.__name__.upper(), url)
         headers = self._headers(**headers or {})
         response = method(url, headers=headers, timeout=timeout, **kwargs)
-        if response.status_code not in (200, 201):
+        if response.status_code not in (200, 201, 204):
             codename = codes.get(response.status_code)[0]
             errtext = response.text.replace('\n', ' ')
             message = '(%s) %s; %s %s' % (response.status_code, codename, response.url, errtext)
diff --git a/tests/conftest.py b/tests/conftest.py
index d1493002..da2ab134 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -323,6 +323,8 @@ def patched_http_call(mocker):
 #  Utility Functions
 # ---------------------------------
 def is_datetime(value):
+    if value is None:
+        return True
     return value > MIN_DATETIME
 
 
diff --git a/tests/test_audio.py b/tests/test_audio.py
index 3abfdbe5..1e1e1d35 100644
--- a/tests/test_audio.py
+++ b/tests/test_audio.py
@@ -68,8 +68,7 @@ def test_audio_Album_attrs(album):
     assert utils.is_metadata(album.key)
     assert utils.is_int(album.librarySectionID)
     assert album.listType == "audio"
-    if album.originallyAvailableAt:
-        assert utils.is_datetime(album.originallyAvailableAt)
+    assert utils.is_datetime(album.originallyAvailableAt)
     assert utils.is_metadata(album.parentKey)
     assert utils.is_int(album.parentRatingKey)
     if album.parentThumb:
@@ -223,8 +222,7 @@ def test_audio_Track_attrs(album):
     assert int(track.index) == 1
     assert utils.is_metadata(track._initpath)
     assert utils.is_metadata(track.key)
-    if track.lastViewedAt:
-        assert utils.is_datetime(track.lastViewedAt)
+    assert utils.is_datetime(track.lastViewedAt)
     assert utils.is_int(track.librarySectionID)
     assert track.listType == "audio"
     # Assign 0 track.media
diff --git a/tests/test_video.py b/tests/test_video.py
index 89ac6ccb..df5fc97b 100644
--- a/tests/test_video.py
+++ b/tests/test_video.py
@@ -171,8 +171,7 @@ def test_video_Movie_attrs(movies):
     assert movie.guid == "com.plexapp.agents.imdb://tt1172203?lang=en"
     assert utils.is_metadata(movie._initpath)
     assert utils.is_metadata(movie.key)
-    if movie.lastViewedAt:
-        assert utils.is_datetime(movie.lastViewedAt)
+    assert utils.is_datetime(movie.lastViewedAt)
     assert int(movie.librarySectionID) >= 1
     assert movie.listType == "video"
     assert movie.originalTitle is None
@@ -496,8 +495,7 @@ def test_video_Show_attrs(show):
     assert utils.is_metadata(show._initpath)
     assert utils.is_int(show.index)
     assert utils.is_metadata(show.key)
-    if show.lastViewedAt:
-        assert utils.is_datetime(show.lastViewedAt)
+    assert utils.is_datetime(show.lastViewedAt)
     assert utils.is_int(show.leafCount)
     assert show.listType == "video"
     assert len(show.locations[0]) >= 10
@@ -770,8 +768,7 @@ def test_video_Season_attrs(show):
     assert season.index == 1
     assert utils.is_metadata(season._initpath)
     assert utils.is_metadata(season.key)
-    if season.lastViewedAt:
-        assert utils.is_datetime(season.lastViewedAt)
+    assert utils.is_datetime(season.lastViewedAt)
     assert utils.is_int(season.leafCount, gte=3)
     assert season.listType == "video"
     assert utils.is_metadata(season.parentKey)