Hi Hannah,
There are a few formatting problems with your nexus file.
There is no "end;" command after the characters block and before beginning the sets block.
Secondly, the format of the charpartition command is a little off. You need semicolons in place of your equals signs, i.e.,
charpartition bypos = pos1:p1 p1b, pos2:p2 p2b, pos3:p3 p3b p3c, pos4:p4, pos5:p5, pos6:p6, pos7:p7 p7b;
rather than
charpartition bypos = pos1=p1 p1b, pos2=p2 p2b, pos3=p3 p3b p3c, pos4=p4, pos5=p5, pos6=p6, pos7=p7 p7b;
Sorry about how confusing the format of that command is, it is part of the Nexus standard, not something that I devised.
There is also an error in some of your model specifications in the garli.conf file. The correct way to specify a model without gamma rate heterogeneity is this:
> ratehetmodel = none
> numratecats = 1
Thanks for your patience, and let me know if you have other issues.
Best,
Derrick