Unable to click UI Button (Unity 4.6) when TimeScale is 0

I’m developing a game and I’m currently creating the pause menu. Whenever I press the key for pause the game (p in my case) it stops just as I want setting Time.timeScale to 0. After it I want to show the buttons for resuming the game, go back to main menu, quit it, etc. but then I’m unable to click them.

I have some testing only buttons using the old GUI features and they still work when the game is paused but I can’t click the Unity 4.6 UI buttons.

I’ve found the solution! The Button is attached to a Canvas that is attached to a GameObject that DontDestroyOnLoad(). But this 4.6 Unity UI needs an EventSystem GameObject which is created when you create the Canvas, but as my Canvas was created in a previous scene, in my current scene (where I wanted to click the Button) I wasn’t able to click it.

Tl;dr: If you have an UI Button you need an EventSystem in the scene.

I hope someone find it useful!