The HK-48 mod i was working on a few years ago, i feel a huge obligation to complete simply bc it was SO near completion. Just a couple of scripts and it could've been released. I was so happy with it was well i think i'm gonna try my hardest to finish it within the next few days.
You can try opening the file that is displayed in your first screenshot with a text editor and change
if (nMaxVersion == 14000) then bone_name = (skinops.getbonenamebylistid m bone_id 1)
else bone_name = (skinops.getbonename m bone_id 1)
bone_name = (skinops.getbonename m bone_id 1)
and try again.
If that doesn't work I'll do some digging, but I may need your help in terms of testing because the issue is related to the version of max you're using.