Using widget to display a score as a result of an event from another blueprint

I created a simple game mockup, using an actor blueprint and a Player Controller, Ive set the scene up in the game world, where the player is shown 9 blocks and must click on the block that is light up with a green light. Now every time the block with a green light is clicked, i would like to display the total score using a widget. But I cannot get the widget to communicate with the actor blueprint which contains the Onblockclick events and its respectives return executions, Ive set up a score integer variable to add 1 to the score integer every time the block that is lit green is clicked. But it just wont work, still very new to UE4

Search for blueprint interfaces. They are designed to achieve exactly that.