(Fixed - own script failed) Some UI Buttons work in Editor - but not in the Standalone build

I've found an issue with the new UI, that I can't seem to fix. One UI in the editor works just fine, but in a build buttons clicks aren't recognized (the buttons are highlighted, but nothing fires). Any ideas?

 

Ah checking my logs looks like i'm getting "Type IPointerClickHandler expected Button received. i:0. Object reference not set to an instance of an object" (which means the call to my script by the button pooped the bed - so it's probably not ugui related..) ** I think** I'll have to double check...

 

OK confirmed it was my bad! If you see that IPointerClickHandler expected error - double check that the function the button is calling, isn't throwing an error!