EventSystem button not calling OnClick on Build, works running in Editor

I have a menu for my arcade style game, where the user can select “Start, Options, Etc…, Exit Game” and it works fine when playing the game in the Editor. When I build and Run a Windows EXE, I can navigate the buttons (EventSystem is in the scene) and it flashes when clicked/activated, just as in the player, but it never calls the actual method linked to OnClick.

Very frustrating. My scenes load fine (I transition from an intro to my title screen) and if I Start with the actual gameplay screen, that seems to work fine.

Well, that was interesting. My GameManager object is a singleton, and the EventSystem didn’t like calling that directly in the runtime version of the game. Calling it indirectly, from a SceneController script, worked just fine.