Hi, I'm using the following script to analyze my data: from yt.config import ytcfg; ytcfg["yt","serialize"] = "False" from yt.mods import * from yt.analysis_modules.star_analysis.api import * pf = load("DD0088/g1e10s1e11dm1e12_0088") my_disk=pf.h.disk([0.5, 0.5, 0.5], [0, 0, 1], 50/pf["kpc"], 10/pf["kpc"]) sfr = StarFormationRate(pf, data_source=my_disk) and I'm getting this error: http://paste.yt-project.org/show/2004/ but yt is actually reading star particles, if I try to get the number of particles or their masses there's no problem (http://paste.yt-project.org/show/2005/), so I suppose the problem is only when reading "creation_time"... or maybe the file is corrupted? I'm using yt-2.2, but with yt-2.3 a similar error occurs. If it's necessary I can upload the data, but its ~250MB. Regards, Fernando.