Spirit help

I've got 59 spirit left over. I'm trying to activate ghost dance which cost 40 spirit (no extra support gems with this). How come it doesn't let me activate it?

My other gems I'm using are herald of ice, heard of thunder, wind dancer,combat frenzy if this helps.

Ghost Dance should only be 30 Spirit without support Gems.

Maybe you dont fullfil the necessary Int requirement? AT Level 18 it's 97 Int for example

My int is a 206 so can't be that.

Hmm... if it can't be activated, the picture of the skill should be darker and there should be a red red exclamation mark on it, if you hover over it, it should tell you why it cant be activated.

some support gems also cost spirits, check your support gems on ghost dance