Hi all, I am trying to read enzo dataset with active particles and getting the following error. There are active particles as indicated by print statement prior to datadump but yt immediately raises this error after loading it. Any help in this regard will be appreciated. yt : [INFO ] 2020-04-13 19:39:50,444 Parameters: current_time = 12.774511689726 yt : [INFO ] 2020-04-13 19:39:50,444 Parameters: domain_dimensions = [256 256 256] yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: domain_left_edge = [0. 0. 0.] yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: domain_right_edge = [1. 1. 1.] yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: cosmological_simulation = 1 yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: current_redshift = 23.138771212879 yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: omega_lambda = 0.6911 yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: omega_matter = 0.3089 yt : [INFO ] 2020-04-13 19:39:50,445 Parameters: hubble_constant = 0.6774 Parsing Hierarchy : 100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 1771/1771 [00:00<00:00, 4770.60it/s] yt : [INFO ] 2020-04-13 19:39:50,937 Gathering a field list (this may take a moment.) Traceback (most recent call last): File "ytdiv.py", line 20, in <module> print(ds.derived_field_list) File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/data_objects/static_output.py", line 216, in ireq self.index File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/data_objects/static_output.py", line 509, in index self, dataset_type=self.dataset_type) File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/frontends/enzo/data_structures.py", line 195, in __init__ GridIndex.__init__(self, ds, dataset_type) File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/geometry/geometry_handler.py", line 58, in __init__ self._detect_output_fields() File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/frontends/enzo/data_structures.py", line 429, in _detect_output_fields ap_fields = self._detect_active_particle_fields() File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/yt/frontends/enzo/data_structures.py", line 388, in _detect_active_particle_fields node = handle["/Grid%08i/Particles/" % g.id] File "h5py/_objects.pyx", line 54, in h5py._objects.with_phil.wrapper File "h5py/_objects.pyx", line 55, in h5py._objects.with_phil.wrapper File "/home/malatif/YT_DEV/yt-conda/lib/python3.7/site-packages/h5py/_hl/group.py", line 262, in __getitem__ oid = h5o.open(self.id, self._e(name), lapl=self._lapl) File "h5py/_objects.pyx", line 54, in h5py._objects.with_phil.wrapper File "h5py/_objects.pyx", line 55, in h5py._objects.with_phil.wrapper File "h5py/h5o.pyx", line 190, in h5py.h5o.open KeyError: "Unable to open object (object 'Particles' doesn't exist)" Best wishes, Latif