Double "Activate" key presses with Mouse and Gamepad.
There are two distinct behaviors associated with this bug, and whether they should be split into two Issues I shall leave up to other developers.
This problem is present using a gamepad (such as an Xbox One controller) or when using the mouse with the "Activate" key mapped to the left mouse button.
Problem 1 - Menu exiting.
When in some menus such as the character creation's race or sign menu pressing the button assigned to "Activate" (default is the A button on an Xbox One controller) intending to select options within that menu such as character race/hair/face, selecting star sign, or trying to click and drag the slider bar will instantly select whatever option you had the cursor over and then bypass to closing the menu as if you had pressed "Next" or "Done".
Problem 2 - Dialogue Topic Doubling.
When in dialogue, trying to select a topic from the right topic selection menu will activate that topic once when the key/button is pressed and once upon releasing the button resulting in the topic being run twice.
This was recently tested on OpenMW-0.43.0-RC1-win64.exe