Hello! I have a vanilla gadget snapshot (one from the lcdm sample run that the code comes with) that  I was able to plot by following the instructions given here: 
http://yt-project.org/docs/3.0/cookbook/tipsy_notebook.html#tipsy-notebook

I then moved on to the 'Making Smoothed Images' section of that page and tried the SlicePlot command.  However, I get the following error:
IndexError: index 32767 is out of bounds for axis 0 with size 32767

Basically, I'm not really sure what that means.  It seems like it's overstepping the bounds of an array, as, for a zero-indexed array of size 32767, index 32767 would be out of bounds by one.  I just wanted to see if anyone else has had this problem, and if so, how they fixed it? Thank you very much! 
-Jared