I have a toolBar with uiButtonItem and some flexible/fixed space item in my storyBoard. with xcode6 they are no more visible, I can still see the edge when switching between buttons in view inspector but they are not visible. I tried to change button tint/ background but they are still not visible.
it turns out that in the Simulated Metric of the ViewController the bottomBar was not set to inferred. I reset it to inferred and all ButtonItems are now shown exactly as before.