diff --git a/pycromanager/acquisition/acq_eng_py/main/acq_notification.py b/pycromanager/acquisition/acq_eng_py/main/acq_notification.py
index efed5751..2be866e2 100644
--- a/pycromanager/acquisition/acq_eng_py/main/acq_notification.py
+++ b/pycromanager/acquisition/acq_eng_py/main/acq_notification.py
@@ -48,10 +48,10 @@ def __init__(self, type, id, phase=None):
         elif phase in [AcqNotification.Camera.PRE_SNAP, AcqNotification.Camera.POST_EXPOSURE,
                      AcqNotification.Camera.PRE_SEQUENCE_STARTED]:
             self.type = AcqNotification.Camera
-            self.id = json.loads(id) # convert from '{'time': 5}' to {'time': 5}
+            self.id = json.loads(id) if isinstance(id, str) else id # convert from '{'time': 5}' to {'time': 5}
         elif phase in [AcqNotification.Hardware.PRE_HARDWARE, AcqNotification.Hardware.POST_HARDWARE]:
             self.type = AcqNotification.Hardware
-            self.id = json.loads(id) # convert from '{'time': 5}' to {'time': 5}
+            self.id = json.loads(id) if isinstance(id, str) else id # convert from '{'time': 5}' to {'time': 5}
         elif phase == AcqNotification.Image.IMAGE_SAVED:
             self.type = AcqNotification.Image
             self.id = id
diff --git a/pycromanager/acquisition/python_backend_acquisitions.py b/pycromanager/acquisition/python_backend_acquisitions.py
index b52e5c6e..a5b4a186 100644
--- a/pycromanager/acquisition/python_backend_acquisitions.py
+++ b/pycromanager/acquisition/python_backend_acquisitions.py
@@ -29,6 +29,8 @@ def __init__(
         napari_viewer=None,
         image_saved_fn: callable=None,
         debug: int=False,
+        # Specificly so the directory arg can be absorbed and ignored without error,
+        **kwargs
     ):
         # Get a dict of all named argument values (or default values when nothing provided)
         arg_names = [k for k in signature(PythonBackendAcquisition.__init__).parameters.keys() if k != 'self']
@@ -36,6 +38,10 @@ def __init__(
         named_args = {arg_name: (l[arg_name] if arg_name in l else
                                      dict(signature(PythonBackendAcquisition.__init__).parameters.items())[arg_name].default)
                                      for arg_name in arg_names }
+        if 'kwargs' in named_args:
+            if 'directory' in named_args['kwargs'] and named_args['kwargs']['directory'] is not None:
+                raise Exception('The directory argument is not supported in Python backend acquisitions')
+            del named_args['kwargs']
         super().__init__(**named_args)
         self._dataset = RAMDataStorage()
         self._finished = False
diff --git a/scripts/python_backend.py b/scripts/python_backend.py
index 3024e19b..7b3e50a9 100644
--- a/scripts/python_backend.py
+++ b/scripts/python_backend.py
@@ -2,7 +2,7 @@
 
 mm_app_path = r"C:\Users\henry\Micro-Manager-nightly"
 config = mm_app_path + r"\MMConfig_demo.cfg"
-start_headless(mm_app_path, config, python_backend=False)
+start_headless(mm_app_path, config, python_backend=True)
 
 with Acquisition() as acq:
     acq.acquire(multi_d_acquisition_events(num_time_points=10))