Hello,
When building game (with linux for linux) and running it in fullscreen mode, GUI buttons don’t work, it seems like they don’t receive click events at all.
When using windows (and building for windows), buttons work fine.
I tested with same resolution (1920 x 1080) in both linux and windows.
I’m using Ubuntu MATE 16.10.
EDIT: When running game in windowed mode, buttons work fine.