From en.wp user Cryptic C62:
- It is possible to break the "Submit feedback" form by doing the following procedure:
- Shrink the browser window so that there is at least an inch or two between the top of the browser and the top of your screen (in other words, don't maximize the window size)
- Drag the "Submit feedback" form as far up as it will go
- Click and hold the top edge of the form to begin resizing, then drag the mouse up to the top of the screen.
- In Monobook, this causes the "submit" and "cancel" buttons to disappear off the bottom of the form.
- In Vector, this causes the bottom chunk of the form to become disconnected (see screenshot).
The screenshot is: https://en.wikipedia.org/wiki/File:VE_Feedback_Break.jpg