Hi all, I've been encountering an error recently whenever I try to save a slice plot, such as: data_sets = yt.load("DD*/output_[0-9][0-9][0-9][0-9]") for ds in data_sets: filename = "density_t={:.3f}_ho.png".format(ds.current_time.in_units('Myr').value) val, loc = ds.find_max('density') print("{:.3f}".format(val)) plt = yt.SlicePlot(ds, L, field, center= loc, width= (size, 'pc')) plt.save(filename) YT seems to think issue is with the call to 'find_max' but a little experimentation shows this is not the case. I'm unable to work out any of what comes back to me asides that: File "plot.py", line 67, in <module> val, loc = ds.find_max('density') File "/opt/apps/pkgs/yt/3.5.1/src/yt/data_objects/static_output.py", line 826, in find_max source.quantities.max_location(field) File "/opt/apps/pkgs/yt/3.5.1/src/yt/data_objects/derived_quantities.py", line 635, in __call__ rv = super(MaxLocation, self).__call__(field, sample_fields) File "/opt/apps/pkgs/yt/3.5.1/src/yt/data_objects/derived_quantities.py", line 591, in __call__ rv = super(SampleAtMaxFieldValues, self).__call__(field, sample_fields) File "/opt/apps/pkgs/yt/3.5.1/src/yt/data_objects/derived_quantities.py", line 68, in __call__ for sto, ds in parallel_objects(chunks, -1, storage = storage): File "/opt/apps/pkgs/yt/3.5.1/src/yt/utilities/parallel_tools/parallel_analysis_interface.py", line 520, in parallel_objects to_share, datatype = 'dict', op = 'join') File "/opt/apps/pkgs/yt/3.5.1/src/yt/utilities/parallel_tools/parallel_analysis_interface.py", line 284, in passage return func(self, *args, **kwargs) File "/opt/apps/pkgs/yt/3.5.1/src/yt/utilities/parallel_tools/parallel_analysis_interface.py", line 723, in par_combine_object data.update(self.comm.recv(source=i, tag=0)) File "mpi4py/MPI/Comm.pyx", line 1173, in mpi4py.MPI.Comm.recv File "mpi4py/MPI/msgpickle.pxi", line 302, in mpi4py.MPI.PyMPI_recv File "mpi4py/MPI/msgpickle.pxi", line 261, in mpi4py.MPI.PyMPI_recv_match Many thanks, Sam Patrick