I have the exact same problem. I just bought the game yesterday via steam and its really frustrating.
​After several trials I actually found a way to recruit Hiravias.
First you should re-install the game and verify the integrity of game cache.
Before talking to Hiravias at Storm Gorge, you should empty up party slot. I'm not sure if this works universally but it worked for me.
But then theres another problem. One of Hiravias' skill is specified as 'Missing abilities -1' and theres no icon.
I tried to ignore this glitch and kept on playing, but I needed to change my party again for some reason.
So I went back to Cad Nua and tried to switch members,,, but it doesn't work again.
The party management window was showing that the change was made but it actually wasn't.
Please come up with a new patch that solves this issue. This is truly a game breaking bug.
I just don't want to proceed without solving this problem.
