I am not sure if I can say this is a bug.
I happened to run split.abund before chimera.vsearch (Plz, don’t ask me why)
Some of my samples were not sequeced well, having only a few reads. Thus should be removed after split.abund. However, the abund.count_table still have the sample names that have no sequences. And this seems to cause a problem with chimera.vsearch. Chimera.vsearch stops after splitting files
It would be nice if split.abund removes samples from abund.count_table if they have no sequences.
For now, I just removed them manually and started chimera.vsearch, which worked fine.