I’ve notice that if I don’t have the max screen resolution in build version of game. The cursor will be where it should be at but when you try clicking buttons, it offsets and you can’t click the button directly. Is this a bug or a programming error?
http://issuetracker.unity3d.com/issues/button-position-is-wrong-on-fullscreen-player-which-aspect-ratio-is-different-then-monitors I believe it’s a unity bug, as I’m experiencing it too. I did find this bug report… I suggest upvoting it as I’ve tried to find a solution, but have yet to find one myself. Best of luck.
This is not a bug in Unity. This is a programming error on your end. If unity had a bug this important almost certainly people have reported it and they would fix it (assuming unit tests of unity itself doesn’t detect such things).
In order to be able to get more help, describe what version of unity you are using, what GUI technology and how you are detecting a click.