diff --git a/clearml/backend_interface/task/task.py b/clearml/backend_interface/task/task.py
index ae18f76a..e53dbb2e 100644
--- a/clearml/backend_interface/task/task.py
+++ b/clearml/backend_interface/task/task.py
@@ -2458,7 +2458,7 @@ class Task(IdObjectBase, AccessMixin, SetupUploadMixin):
         return {p.id: p.name for p in all_responses}
 
     def _get_all_events(
-        self, max_events=100, batch_size=500, order='asc', event_type=None, unique_selector=itemgetter("url")
+        self, max_events=100, batch_size=500, order='asc', event_type=None, unique_selector=None
     ):
         # type: (int, int, str, str, Callable[[dict], Any]) -> Union[List[Any], Set[Any]]
         """
@@ -2479,6 +2479,16 @@ class Task(IdObjectBase, AccessMixin, SetupUploadMixin):
         """
         batch_size = max_events or batch_size
 
+        def apply_unique_selector(events_set, evs):
+            # type: (Set[Any], List[dict]) -> ()
+            try:
+                events_set.update(map(unique_selector, evs))
+            except TypeError:
+                self.log.error(
+                    "Failed applying unique_selector on events (note the selector's result must be hashable)"
+                )
+                raise
+
         log_events = self.send(events.GetTaskEventsRequest(
             task=self.id,
             order=order,
@@ -2490,7 +2500,8 @@ class Task(IdObjectBase, AccessMixin, SetupUploadMixin):
         total_events = log_events.response.total
         scroll = log_events.response.scroll_id
         if unique_selector:
-            events_list = set(map(unique_selector, log_events.response.events))
+            events_list = set([])
+            apply_unique_selector(events_list, log_events.response.events)
         else:
             events_list = log_events.response.events
 
@@ -2505,7 +2516,7 @@ class Task(IdObjectBase, AccessMixin, SetupUploadMixin):
             scroll = log_events.response.scroll_id
             returned_count += log_events.response.returned
             if unique_selector:
-                events_list.update(log_events.response.events)
+                apply_unique_selector(events_list, log_events.response.events)
             else:
                 events_list.extend(log_events.response.events)