[UMG] Can't click Buttons on Inteface Widget

Hello Community,
I attached an UMG Interface that i created to a static mesh

http://puu.sh/hKUVu/1a6b78c412.jpg

I set every button to visible but when I play the game, I can’t click any button(or at least get an hover event).

But I can click the red button in the corner.

I tried everything but nothing seems to work, I hope I get a fast answer.

After trying everything, I’ve now figured it out.
There is something wrong with Unreal Engine 4.7.
I started 4.8 Preview 2 and now everything works absolute fine.