Win 7 GTX 970
Broken: 2.75 official release (1.7.2015)
Worked: 2.74 official release
When uwrapping objects, i heavily use shortcuts. To unwrap using "follow active quad" i just press "u f o". Easy to remember and very fast, no mouse needed.
The "o" of "u f o" doesnt work anymore, you can not confirm the unwraping options anymore.
Visually the "O" of "Ok" is not underlined as it was in the previous version, therefore indicating, that you can not press a key anymore to select it.
Exact steps for others to reproduce the error
Select a face of the standart cube.
Press "u" to open the unwrap menu.
Press "f" to select the "follow active quad" option
to confirm the settings, you have to confirm now with the mouse, click on "Ok". Earlier you just hit "o".