If it's a spell I always /cast #XX for what number that spell is memmed on the spell bar. If it's an alt, I /alt act the #of that alt, which you can find by looking on your aa window, highlighting whichever activatable alt and reading the description.
3 days ago maybe he was using the old zip? I put in support for new ranked aa's in the zip released on the 30th but since I don't know which version he was running it's hard to know why it fails...
After a couple of days away and reading the comments it got it to work again as normal with the new changes in alt ranks
PetBuffName6=Hobble of Spirits III
PetBuffSpell6=Hobble of Spirits
I did try some variations originally, I thought I had tried this combination before, guess not... oops!
I was also trying straight command /casting "Hobble Spirits" alt which was failing but /casting 126:alt was working
Sorry I didn't post any versions, they were just the "Current" Loader versions, but I see that's important due to posts ageing.