So I do the command /avatar bending add (Id) airbending. It says I am an airbender but abilities don't come up.

Closed due to having had no update in a long time. Thanks for delivering assistance @hdkd4

I don't work here, but I would still like to help. Are you using the mod version 1.6.0 or 1.5.17? If you're not using either of them, I would suggest updating the mod to 1.5.17, due to there being no waterbending in 1.6.0 as of yet. There may also be a problem with another mod in your mods folder.

What exactly do you mean by that? Does the window pop up but there isn't any abilities? Or does the window not pop up at all?

So no window pops up and no fire symbol is added next to other bending.