Return of Reckoning

Has anyone else come across this problem before? I do everything in my power to cast Tzeentch's Firestorm, I have line of sight, its in range, but I can only ever start the cast. As soon as the cast bar and animation begin it just stops. When I'm in the city it works just fine, otherwise it ...

Has anyone else come across this problem before? I do everything in my power to cast Tzeentch's Firestorm, I have line of sight, its in range, but I can only ever start the cast. As soon as the cast bar and animation begin it just stops. When I'm in the city it works just fine, otherwise it doesn't ...