Yes, it returned the good value that was pressed in the scene. But then the hang and error about exceeding the cycles.
No, I did not try to add "tampon" state containing a "next frame event" because I do not know what it is .
What happens here is that your fsm is trying to make an infinite amount of actions during a single frame.
I guess that your FSM is making a loop, just take a look at it. It must be doing something like "check bool" in a state, and send an event to an other state when the bool is true. Then it gets back to the check bool state, and as the bool is still true for this frame sends the event once again. As you aren't telling it when to take a breack (wait for the next frame before checking again if the bool i strue), it is trying to check the bool endlessly, holding the release of the current frame.
Find the "next frame event" (or "wait" can also do the trick) and put it on the state that is entered when the bool is true. This way as soon as it enters this state, it will stop the looping for the current frame.
I hope that I was clear enough XD. Getting into it was a bit of a pain for me too, don't worry it's normal ;-)