How I got here:
With 2 AP left, I cast Phoenix Dive, reducing AP to 1. I went to cast daggers, and the cost is correct, and the tooltip says it costs 1, but it will not allow me to cast it. See image below.
![[Linked Image]](http://i.imgur.com/gmaw9h7.jpg)
You can see in the image the searing daggers is greyed out. Likewise, trying to cast it anyways will not work.
Hope this helps.
Bonus Bug:
Just went back to game and noticed my Impalement is NOT greyed out, and I don't have the AP to cast that either (not as serious since it still won't let me cast it).