New issue 1325: Fields cannot be retrieved properly from ray object created from reloaded ytdata https://bitbucket.org/yt_analysis/yt/issues/1325/fields-cannot-be-retrieved-... Bili Dong: I'm trying to create a ray object from a saved ytdata and access its fields using the following script: ```python import yt ds = yt.load('FIRE_M12i_ref11/snapshot_600.hdf5') ad = ds.all_data() ad['PartType0', 'Density'] path = ad.save_as_dataset() ds_reload = yt.load(path) ray_reload = ds_reload.ray(ds_reload.domain_left_edge, ds_reload.domain_right_edge) print(ray_reload['PartType0', 'Density']) print(ray_reload['t']) ``` And the outputs are: ``` [] code_mass/code_length**3 [ 0. 0.25 0.5 0.5078125 0.515625 0.5234375 0.53125 0.546875 0.5625 0.59375 0.625 0.6875 0.75 0.875 ] dimensionless ``` Somehow `ray_reload['PartType0', 'Density']` is empty, which is not what I expected.