Why can't I target creatures with a hotkey?

Question

I'm hitting the space bar to attack creatures and I get that message: "adjust your combat settings to attack this player", so I can't targetable, any explanation why? It wasn't happening a while ago.

Answer 1

Maybe because your battle list was showing players so, while clicking space bar, you were trying to target a player.

Sometimes, if you open a second battle window that problem can happen, to solve it, just close both battles and re-open it.