Minions stopped summoing

The Local Bone 117 Minion Union appears to be in strike, because mine have refused to summon all of a sudden. I finished Ogham Village and for a couple of T5 gems, so I added bone storm and raise zombie, also taking the opportunity to swap out wand and septor for sector and shield. Suddenly, I have Red exclamation point next to my skeletal archers, with the warning that I don't have the required spirit. I still have 17 spirit in reserve, so this strikes weird. I tried reducing the count to one, with no effect. I tried removing all new skills and replacing all original equipment, all to no effect. My minions just don't work. I can't tell if it's bugged or if I did something inadvertently. Thoughts?

Thank you.