Malatina's Course of Terror
I cannot dig up the keys. The cannons will not select after they pop up from the tile, so they cannot be fired.
If you are a warden, the buff that the cannon gives you to select a target may be hidden benching your pets. You can always press alt-1 to cast it though.
The keys I have issues sometimes as we'll. I just keep click spamming them all over the tile until it works