Hello all, yt has some of the greatest plotting capabilities, and I greatly enjoy working with yt! Recently I have begun to work with hdf5 data from a large scale galaxy simulation (illustris) and I was wondering how I can work with the data, is there a general munging procedure for getting it into the correct yt format? When I try to plot 

import yt

ds = yt.load("Groups_hdf5_plt_cnt_0150")
yt.SlicePlot(ds, 'x', "density", width = (800.0, 'kpc')).save()
yt.SlicePlot(ds, 'y', "density", width = (800.0, 'kpc')).save()
yt.SlicePlot(ds, 'z', "density", width = (800.0, 'kpc')).save()

I get the following error:

/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/yt/frontends/gadget_fof/data_structures.pyc in _parse_parameter_file(self)

    151         self.periodicity = (True, True, True)

    152         self.current_redshift = hvals["Redshift"]

--> 153         self.omega_lambda = hvals["OmegaLambda"]

    154         self.omega_matter = hvals["Omega0"]

    155         self.hubble_constant = hvals["HubbleParam"]

KeyError: 'OmegaLambda'

I am guessing this is because the field entries do not match up.

Any help is much appreciated!