I’m using 4.4.1 release, and at the moment, creating and adding a UMG widget to the viewport causes gamepad controls to break in editor (I’m using a first person style control scheme, and a wired Xbox 360 controller). Specifically, play in new editor window will make gamepad controls not work at all. Playing in selected viewport will work until you happen to click your mouse outside of the viewport (which is easy to do because for some reason, with a UMG widget enabled, mouse tracking in your Windows desktop is still enabled; you can see your mouse going beyond the UE4 editor boundaries if you move it enough).
Thanks for the bug report, has been fixed in master/4.5.
Cheers,
Nick
Thanks, highly anticipating 4.5 then!
Me too! 
I’d just like to add that changing the viewport size also breaks gamepad focus if any UMG widgets are on screen. Presumably related to the same bug
Nope, not an issue in 4.5, just tried it with a begin play, with a delay that spawned some new UI after I was playing the game, no focus stealing occurred.
Hi Nick.
Apologies. After i posted i realized that my events were still referencing old methods of spawning actors.
Once i corrected my mistake and made the Widget trigger the spawn everything was working fine again.
I deleted my comment shortly after, and i am assuming you were responding to my post.
Apologies once again. And thank you and the guys at epic for getting UMG working