Hi bwhhy,
I just put together a quick test and everything worked correctly. Perhaps the steps I used will help you:
- Launch UE 4.10.4; Create a new C++ project with Basic Code, Desktop/Console, Maximum Quality, and No Starter Content
- Add a Player Controller C++ class and use the default constructor so show the mouse cursor, and enable click and mouse-over events
- Open the C++ Game Mode class that was generated with the project and use the default constructor to set the default Player Controller class to my new class
- Edit the Project Settings to use the C++ Game Mode class (Maps & Modes ā Default Modes ā Default GameMode)
- Add a new Pawn C++ class with a click function that simply logs a message to the output log and registers that function in the default constructor
- Add a blueprint class derived from my C++ Pawn class and add a cube to its components
- Place one of my blueprint Pawns into the scene in front of the player
- Play the level, click the cube of my blueprint Pawn class, view the Output Log and see that the message appeared