What action are you using to change the alpha from 0 to 1?
I see in your screenshot:
https://i.imgsafe.org/790bef29a0.jpg you have a send event when the player tag enters the signpost trigger area. Check that when the player enters the trigger, that this is sending the event you have set. When that event is sent, what are the actions under your state 'State 2'?
If you aren't already I suggest using the action 'U Gui Canvas Group Set Properties' i believe it comes with the Ugui pack in the playmaker ecosystem.
Using this, you could even have the ui fade in using a float variable for the alpha, set the action to every frame, and use an ease float to take the alpha from 0 to 1 gradually.
I hope that helped and didn't add more confusion