AC Brotherhood PC can't fire cannons

[Kore]

I'm stuck at the Vilified part. At the practice shooting with the cannons part I could shoot but now I can click with my mouse or push any key I want, the cannon just doesn't shoot... No one on the internet seems to have this problem and I really don't know how to solve this... Does anyone know the solution?

[Kekyoin]

...turns out the keys for firing is spacebar!

[Kore]

it had nothing to do with me, there was a bug in the game. When I uninstalled and reinstalled it again it was working.

[FreedomGaming02]

Ive also been having this problem