I can't figure out how to do it. I'm about 8 turns in as the CSA and the option is still greyed out whenever I select an active 1 or 2 star general. I read the wiki and the FAQ and I can't understand why it won't let me.
I've applied the v1.15 patch, and one theory I've been considering is that the patch is bugged, because I could form divisions before the patch. Any ideas?