Tutorial in question link:
The tutorial located at the aobe link is now outdated. As of at least 4.14 when you follow all of the steps you will not be able to interact with the buttons (you can click once using the initial PIE focusing click, and not at all in stand alone). It appears between 4.9 - 4.14 a change occurred where you now need to specify to set the input mode to allow for UI interactions.
On page 2 (https://docs.unrealengine.com/latest/INT/Programming/Tutorials/UMG/2/index.html). When configuring the game mode add the following lines to the “BeginPlay” function:
FInputModeDataBase* inputMode = new FInputModeGameUIOnly();
I ended up moving the above tid bit to a “MenuPlayerController” class just because it seemed a bit cleaner to me. If there is a better solution or I am doing something way off and anyone feels like sharing, thanks in advance.