diff --git a/nvflare/app_common/workflows/cyclic_ctl.py b/nvflare/app_common/workflows/cyclic_ctl.py
index a3f1631d80..524c26359f 100644
--- a/nvflare/app_common/workflows/cyclic_ctl.py
+++ b/nvflare/app_common/workflows/cyclic_ctl.py
@@ -161,6 +161,10 @@ def _get_relay_orders(self, fl_ctx: FLContext) -> Union[List[Client], None]:
         self._last_client = targets[-1]
         return targets
 
+    def _stop_workflow(self, task: Task):
+        self.cancel_task(task)
+        self._is_done = True
+
     def _process_result(self, client_task: ClientTask, fl_ctx: FLContext):
         # submitted shareable is stored in client_task.result
         # we need to update task.data with that shareable so the next target
@@ -176,7 +180,9 @@ def _process_result(self, client_task: ClientTask, fl_ctx: FLContext):
                 self._last_learnable = self.shareable_generator.shareable_to_learnable(result, fl_ctx)
             except Exception as ex:
                 if rc != ReturnCode.EARLY_TERMINATION:
+                    self._stop_workflow(task)
                     self.log_error(fl_ctx, f"exception {secure_format_exception(ex)} from shareable_to_learnable")
+                    return
                 else:
                     self.log_warning(
                         fl_ctx,
@@ -186,15 +192,21 @@ def _process_result(self, client_task: ClientTask, fl_ctx: FLContext):
             if rc == ReturnCode.EARLY_TERMINATION:
                 if self._allow_early_termination:
                     # the workflow is done
-                    self.cancel_task(task)
+                    self._stop_workflow(task)
                     self.log_info(fl_ctx, f"Stopping workflow due to {rc} from client {client_task.client.name}")
-                    self._is_done = True
                     return
                 else:
                     self.log_warning(
                         fl_ctx,
                         f"Ignored {rc} from client {client_task.client.name} because early termination is not allowed",
                     )
+        else:
+            self._stop_workflow(task)
+            self.log_error(
+                fl_ctx,
+                f"Stopping workflow due to result from client {client_task.client.name} is not a Shareable",
+            )
+            return
 
         # prepare task shareable data for next client
         task.data = self.shareable_generator.learnable_to_shareable(self._last_learnable, fl_ctx)
diff --git a/tests/unit_test/app_common/workflow/cyclic_ctl_test.py b/tests/unit_test/app_common/workflow/cyclic_ctl_test.py
index 4fb88236dd..9f17e310e2 100644
--- a/tests/unit_test/app_common/workflow/cyclic_ctl_test.py
+++ b/tests/unit_test/app_common/workflow/cyclic_ctl_test.py
@@ -55,6 +55,18 @@
 ]
 
 
+def gen_shareable(is_early_termination: bool = False, is_not_shareable: bool = False):
+    if is_not_shareable:
+        return [1, 2, 3]
+    return_result = Shareable()
+    if is_early_termination:
+        return_result.set_return_code(ReturnCode.EARLY_TERMINATION)
+    return return_result
+
+
+PROCESS_RESULT_TEST_CASES = [gen_shareable(is_early_termination=True), gen_shareable(is_not_shareable=True)]
+
+
 class TestCyclicController:
     @pytest.mark.parametrize("order,active_clients,expected_result", ORDER_TEST_CASES)
     def test_get_relay_orders(self, order, active_clients, expected_result):
@@ -90,7 +102,8 @@ def test_control_flow_call_relay_and_wait(self):
 
                 mock_method.assert_called_once()
 
-    def test_process_result(self):
+    @pytest.mark.parametrize("return_result", PROCESS_RESULT_TEST_CASES)
+    def test_process_result(self, return_result):
         ctl = CyclicController(
             persist_every_n_rounds=0, snapshot_every_n_rounds=0, num_rounds=1, allow_early_termination=True
         )
@@ -101,7 +114,6 @@ def test_process_result(self):
             Client("site-2", SITE_2_ID),
         ]
 
-        abort_signal = Signal()
         fl_ctx = FLContext()
         with patch.object(ctl, "cancel_task") as mock_method, patch.object(
             ctl.shareable_generator, "learnable_to_shareable"
@@ -109,9 +121,6 @@ def test_process_result(self):
             mock_method1.return_value = Shareable()
             mock_method2.return_value = Learnable()
 
-            return_result = Shareable()
-            return_result.set_return_code(ReturnCode.EARLY_TERMINATION)
-
             client_task = ClientTask(
                 client=Mock(),
                 task=Task(