diff --git a/pype/ftrack/actions/action_attributes_remapper.py b/pype/ftrack/actions/action_attributes_remapper.py
index 759b5765e5..a0393ece40 100644
--- a/pype/ftrack/actions/action_attributes_remapper.py
+++ b/pype/ftrack/actions/action_attributes_remapper.py
@@ -281,7 +281,4 @@ class AttributesRemapper(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     AttributesRemapper(session, plugins_presets).register()
diff --git a/pype/ftrack/actions/action_client_review_sort.py b/pype/ftrack/actions/action_client_review_sort.py
index 6a659ce5e3..91926c2874 100644
--- a/pype/ftrack/actions/action_client_review_sort.py
+++ b/pype/ftrack/actions/action_client_review_sort.py
@@ -55,11 +55,8 @@ class ClientReviewSort(BaseAction):
 
 def register(session, plugins_presets={}):
     '''Register action. Called when used as an event plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
-    action_handler = ClientReviewSort(session, plugins_presets)
-    action_handler.register()
+    ClientReviewSort(session, plugins_presets).register()
 
 
 def main(arguments=None):
diff --git a/pype/ftrack/actions/action_component_open.py b/pype/ftrack/actions/action_component_open.py
index 33f4d38890..98d773dba6 100644
--- a/pype/ftrack/actions/action_component_open.py
+++ b/pype/ftrack/actions/action_component_open.py
@@ -68,12 +68,6 @@ class ComponentOpen(BaseAction):
 def register(session, plugins_presets={}):
     '''Register action. Called when used as an event plugin.'''
 
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     ComponentOpen(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_create_cust_attrs.py b/pype/ftrack/actions/action_create_cust_attrs.py
index 47a6bb5d5f..ac6dcb0fd7 100644
--- a/pype/ftrack/actions/action_create_cust_attrs.py
+++ b/pype/ftrack/actions/action_create_cust_attrs.py
@@ -572,12 +572,6 @@ class CustomAttributes(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     CustomAttributes(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_create_folders.py b/pype/ftrack/actions/action_create_folders.py
index 269316e052..44e9741bab 100644
--- a/pype/ftrack/actions/action_create_folders.py
+++ b/pype/ftrack/actions/action_create_folders.py
@@ -327,9 +327,6 @@ class PartialDict(dict):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     CreateFolders(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_create_project_structure.py b/pype/ftrack/actions/action_create_project_structure.py
index 74d458b5f8..c39c717b11 100644
--- a/pype/ftrack/actions/action_create_project_structure.py
+++ b/pype/ftrack/actions/action_create_project_structure.py
@@ -198,9 +198,6 @@ class CreateProjectFolders(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     CreateProjectFolders(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_cust_attr_doctor.py b/pype/ftrack/actions/action_cust_attr_doctor.py
index af5fe2dc4a..0469b3a1e6 100644
--- a/pype/ftrack/actions/action_cust_attr_doctor.py
+++ b/pype/ftrack/actions/action_cust_attr_doctor.py
@@ -9,7 +9,7 @@ from pype.ftrack import BaseAction
 
 
 class CustomAttributeDoctor(BaseAction):
-    
+
     ignore_me = True
     #: Action identifier.
     identifier = 'custom.attributes.doctor'
@@ -294,9 +294,6 @@ class CustomAttributeDoctor(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     CustomAttributeDoctor(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_delete_asset.py b/pype/ftrack/actions/action_delete_asset.py
index 1b1e7fc905..106c81758a 100644
--- a/pype/ftrack/actions/action_delete_asset.py
+++ b/pype/ftrack/actions/action_delete_asset.py
@@ -85,7 +85,7 @@ class DeleteAsset(BaseAction):
                 'type': 'asset',
                 'name': entity['name']
             })
-            
+
             if av_entity is None:
                 return {
                     'success': False,
@@ -314,12 +314,6 @@ class DeleteAsset(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     DeleteAsset(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_delete_asset_byname.py b/pype/ftrack/actions/action_delete_asset_byname.py
index 2431b2311e..4a3807f8f0 100644
--- a/pype/ftrack/actions/action_delete_asset_byname.py
+++ b/pype/ftrack/actions/action_delete_asset_byname.py
@@ -135,12 +135,6 @@ class AssetsRemover(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     AssetsRemover(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_djvview.py b/pype/ftrack/actions/action_djvview.py
index 58914fbc1e..9da12dd67c 100644
--- a/pype/ftrack/actions/action_djvview.py
+++ b/pype/ftrack/actions/action_djvview.py
@@ -220,8 +220,6 @@ class DJVViewAction(BaseAction):
 
 def register(session, plugins_presets={}):
     """Register hooks."""
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     DJVViewAction(session, plugins_presets).register()
 
diff --git a/pype/ftrack/actions/action_job_killer.py b/pype/ftrack/actions/action_job_killer.py
index 717f87e879..64fb99133d 100644
--- a/pype/ftrack/actions/action_job_killer.py
+++ b/pype/ftrack/actions/action_job_killer.py
@@ -121,12 +121,6 @@ class JobKiller(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     JobKiller(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_multiple_notes.py b/pype/ftrack/actions/action_multiple_notes.py
index 6e28b7bed6..bd51cb2984 100644
--- a/pype/ftrack/actions/action_multiple_notes.py
+++ b/pype/ftrack/actions/action_multiple_notes.py
@@ -115,9 +115,6 @@ class MultipleNotes(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     MultipleNotes(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_prepare_project.py b/pype/ftrack/actions/action_prepare_project.py
index e914fa74f0..d645748f6f 100644
--- a/pype/ftrack/actions/action_prepare_project.py
+++ b/pype/ftrack/actions/action_prepare_project.py
@@ -372,7 +372,4 @@ class PrepareProject(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     PrepareProject(session, plugins_presets).register()
diff --git a/pype/ftrack/actions/action_rv.py b/pype/ftrack/actions/action_rv.py
index 6b6591355f..69c6624b71 100644
--- a/pype/ftrack/actions/action_rv.py
+++ b/pype/ftrack/actions/action_rv.py
@@ -328,8 +328,6 @@ class RVAction(BaseAction):
 
 def register(session, plugins_presets={}):
     """Register hooks."""
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     RVAction(session, plugins_presets).register()
 
diff --git a/pype/ftrack/actions/action_start_timer.py b/pype/ftrack/actions/action_start_timer.py
index 36752a1edc..292789e9f3 100644
--- a/pype/ftrack/actions/action_start_timer.py
+++ b/pype/ftrack/actions/action_start_timer.py
@@ -26,7 +26,7 @@ class StartTimer(BaseAction):
 
         user.start_timer(entity, force=True)
         self.session.commit()
-        
+
         self.log.info(
             "Starting Ftrack timer for task: {}".format(entity['name'])
         )
@@ -37,7 +37,4 @@ class StartTimer(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     StartTimer(session, plugins_presets).register()
diff --git a/pype/ftrack/actions/action_sync_hier_attrs_local.py b/pype/ftrack/actions/action_sync_hier_attrs_local.py
index 05a70461a1..289abd0122 100644
--- a/pype/ftrack/actions/action_sync_hier_attrs_local.py
+++ b/pype/ftrack/actions/action_sync_hier_attrs_local.py
@@ -309,9 +309,6 @@ class SyncHierarchicalAttrs(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     SyncHierarchicalAttrs(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_sync_to_avalon_local.py b/pype/ftrack/actions/action_sync_to_avalon_local.py
index ddf8ed6571..61050f9883 100644
--- a/pype/ftrack/actions/action_sync_to_avalon_local.py
+++ b/pype/ftrack/actions/action_sync_to_avalon_local.py
@@ -263,11 +263,4 @@ class SyncToAvalon(BaseAction):
 
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
-
-    # Validate that session is an instance of ftrack_api.Session. If not,
-    # assume that register is being called from an old or incompatible API and
-    # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     SyncToAvalon(session, plugins_presets).register()
diff --git a/pype/ftrack/actions/action_test.py b/pype/ftrack/actions/action_test.py
index a2bc8bf892..58f7210e3b 100644
--- a/pype/ftrack/actions/action_test.py
+++ b/pype/ftrack/actions/action_test.py
@@ -43,9 +43,6 @@ class TestAction(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     TestAction(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/actions/action_thumbnail_to_childern.py b/pype/ftrack/actions/action_thumbnail_to_childern.py
index 101b678512..7d189cf652 100644
--- a/pype/ftrack/actions/action_thumbnail_to_childern.py
+++ b/pype/ftrack/actions/action_thumbnail_to_childern.py
@@ -68,8 +68,6 @@ class ThumbToChildren(BaseAction):
 
 def register(session, plugins_presets={}):
     '''Register action. Called when used as an event plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     ThumbToChildren(session, plugins_presets).register()
 
diff --git a/pype/ftrack/actions/action_thumbnail_to_parent.py b/pype/ftrack/actions/action_thumbnail_to_parent.py
index c382d9303c..efafca4a96 100644
--- a/pype/ftrack/actions/action_thumbnail_to_parent.py
+++ b/pype/ftrack/actions/action_thumbnail_to_parent.py
@@ -90,8 +90,6 @@ class ThumbToParent(BaseAction):
 
 def register(session, plugins_presets={}):
     '''Register action. Called when used as an event plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     ThumbToParent(session, plugins_presets).register()
 
diff --git a/pype/ftrack/actions/action_where_run_ask.py b/pype/ftrack/actions/action_where_run_ask.py
index 0351c09909..795c2664cc 100644
--- a/pype/ftrack/actions/action_where_run_ask.py
+++ b/pype/ftrack/actions/action_where_run_ask.py
@@ -40,7 +40,4 @@ class ActionAskWhereIRun(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     ActionAskWhereIRun(session, plugins_presets).register()
diff --git a/pype/ftrack/actions/action_where_run_show.py b/pype/ftrack/actions/action_where_run_show.py
index 7fea23e3b7..48618f0251 100644
--- a/pype/ftrack/actions/action_where_run_show.py
+++ b/pype/ftrack/actions/action_where_run_show.py
@@ -80,7 +80,4 @@ class ActionShowWhereIRun(BaseAction):
 def register(session, plugins_presets={}):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     ActionShowWhereIRun(session, plugins_presets).register()
diff --git a/pype/ftrack/events/action_sync_hier_attrs.py b/pype/ftrack/events/action_sync_hier_attrs.py
index c9d968ee5d..23ac319261 100644
--- a/pype/ftrack/events/action_sync_hier_attrs.py
+++ b/pype/ftrack/events/action_sync_hier_attrs.py
@@ -220,7 +220,7 @@ class SyncHierarchicalAttrs(BaseAction):
             if job['status'] in ('queued', 'running'):
                 job['status'] = 'failed'
             session.commit()
-            
+
             if self.interface_messages:
                 self.show_interface_from_dict(
                     messages=self.interface_messages,
@@ -341,9 +341,6 @@ class SyncHierarchicalAttrs(BaseAction):
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
 
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     SyncHierarchicalAttrs(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/events/action_sync_to_avalon.py b/pype/ftrack/events/action_sync_to_avalon.py
index 51a4ae9475..7b5f94f216 100644
--- a/pype/ftrack/events/action_sync_to_avalon.py
+++ b/pype/ftrack/events/action_sync_to_avalon.py
@@ -296,9 +296,6 @@ def register(session, plugins_presets):
     # Validate that session is an instance of ftrack_api.Session. If not,
     # assume that register is being called from an old or incompatible API and
     # return without doing anything.
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     SyncToAvalon(session, plugins_presets).register()
 
 
diff --git a/pype/ftrack/events/event_del_avalon_id_from_new.py b/pype/ftrack/events/event_del_avalon_id_from_new.py
index 6f6320f51b..e5c4b1be45 100644
--- a/pype/ftrack/events/event_del_avalon_id_from_new.py
+++ b/pype/ftrack/events/event_del_avalon_id_from_new.py
@@ -53,7 +53,5 @@ class DelAvalonIdFromNew(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     DelAvalonIdFromNew(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_next_task_update.py b/pype/ftrack/events/event_next_task_update.py
index 18a7abf328..51ccb2f057 100644
--- a/pype/ftrack/events/event_next_task_update.py
+++ b/pype/ftrack/events/event_next_task_update.py
@@ -88,7 +88,5 @@ class NextTaskUpdate(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     NextTaskUpdate(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_radio_buttons.py b/pype/ftrack/events/event_radio_buttons.py
index 9c6f2d490a..917c7a49e6 100644
--- a/pype/ftrack/events/event_radio_buttons.py
+++ b/pype/ftrack/events/event_radio_buttons.py
@@ -36,7 +36,5 @@ class Radio_buttons(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     Radio_buttons(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_sync_hier_attr.py b/pype/ftrack/events/event_sync_hier_attr.py
index 5ddc2394af..8031ec9e55 100644
--- a/pype/ftrack/events/event_sync_hier_attr.py
+++ b/pype/ftrack/events/event_sync_hier_attr.py
@@ -209,7 +209,5 @@ class SyncHierarchicalAttrs(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     SyncHierarchicalAttrs(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_sync_to_avalon.py b/pype/ftrack/events/event_sync_to_avalon.py
index 4e7b208726..a25866be65 100644
--- a/pype/ftrack/events/event_sync_to_avalon.py
+++ b/pype/ftrack/events/event_sync_to_avalon.py
@@ -122,8 +122,4 @@ class Sync_to_Avalon(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-
-    if not isinstance(session, ftrack_api.session.Session):
-        return
-
     Sync_to_Avalon(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_test.py b/pype/ftrack/events/event_test.py
index 94d99dbf67..a909aa5510 100644
--- a/pype/ftrack/events/event_test.py
+++ b/pype/ftrack/events/event_test.py
@@ -8,7 +8,7 @@ from pype.ftrack import BaseEvent
 class Test_Event(BaseEvent):
 
     ignore_me = True
-    
+
     priority = 10000
 
     def launch(self, session, event):
@@ -22,7 +22,5 @@ class Test_Event(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     Test_Event(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_thumbnail_updates.py b/pype/ftrack/events/event_thumbnail_updates.py
index 51bb15a4c7..ae6f8adb5e 100644
--- a/pype/ftrack/events/event_thumbnail_updates.py
+++ b/pype/ftrack/events/event_thumbnail_updates.py
@@ -47,7 +47,5 @@ class ThumbnailEvents(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     ThumbnailEvents(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_user_assigment.py b/pype/ftrack/events/event_user_assigment.py
index fe8b331629..61699d736c 100644
--- a/pype/ftrack/events/event_user_assigment.py
+++ b/pype/ftrack/events/event_user_assigment.py
@@ -233,7 +233,5 @@ def register(session, plugins_presets):
     """
     Register plugin. Called when used as an plugin.
     """
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     UserAssigmentEvent(session, plugins_presets).register()
diff --git a/pype/ftrack/events/event_version_to_task_statuses.py b/pype/ftrack/events/event_version_to_task_statuses.py
index 85a31383d5..66a55c0cf7 100644
--- a/pype/ftrack/events/event_version_to_task_statuses.py
+++ b/pype/ftrack/events/event_version_to_task_statuses.py
@@ -71,7 +71,5 @@ class VersionToTaskStatus(BaseEvent):
 
 def register(session, plugins_presets):
     '''Register plugin. Called when used as an plugin.'''
-    if not isinstance(session, ftrack_api.session.Session):
-        return
 
     VersionToTaskStatus(session, plugins_presets).register()
diff --git a/pype/ftrack/lib/ftrack_base_handler.py b/pype/ftrack/lib/ftrack_base_handler.py
index 9eda74f0f3..9821bfd81f 100644
--- a/pype/ftrack/lib/ftrack_base_handler.py
+++ b/pype/ftrack/lib/ftrack_base_handler.py
@@ -31,8 +31,21 @@ class BaseHandler(object):
 
     def __init__(self, session, plugins_presets={}):
         '''Expects a ftrack_api.Session instance'''
-        self._session = session
         self.log = Logger().get_logger(self.__class__.__name__)
+        if not isinstance(session, ftrack_api.session.Session):
+            self.log.warning((
+                "Session object entered with args is instance of \"{}\""
+                " but expected instance is \"{}\"."
+            ).format(
+                str(type(session)),
+                str(ftrack_api.session.Session.__qualname__)
+            ))
+            self.register = self.register_without_session
+            self._session = None
+
+            return
+
+        self._session = session
 
         # Using decorator
         self.register = self.register_decorator(self.register)