ToME: the Tales of Maj'Eyal

I gained an equilibrium bar after unlocking the Harmony tree and putting a few points in the talents. And the bar remained after I removed all the points.

You can hide it. Unlock the interface (button is in the lower right corner), right click the move icon above the bars that just appeared, and there you can choose to hide or show resources.

It's not clear to me whether this is a bug, but it can have in-game effects beyond just the bar appearing. For instance, if you gain a mana bar in a similar way, then enemies can use Manaclash on you.

I dont consider it a bug; you did dable with the arcane forces, you pay the consequences !