Created attachment 938841 [details]
image

Description of problem:

when,'operation canceled',pop up window come up,there's no way to reach, 'close' button even though it is the only one,pressing enter does not do anything and pressing tab doesn't prompt any selection either(see image)

*note*
esc key does close this menu but it is very un-intuitive and I doubt that the majority of our users know about that option.

Version-Release number of selected component (if applicable):
vt3

How reproducible:
100%

Steps to Reproduce:
1.go to new vm menu,and enter an invalid name,press enter

Actual results:
The 'operation canceled' pop up window come up without context

Expected results:
a context should be added/every pop up window with buttons should have context and tab key should prompt a button switch in a way that makes sense.

Additional info: