A niche bug - attempting to create a &redlink=1 page that is protected from creation on a wiki on which you have not edited before, but which you *can* create (e.g. with the staff userright), means the "Welcome to Wikipedia" VisualEditor prompt is not closable. The buttons don't work at all.
Screenshot of the issue (on svwp with Google Translate enabled on Chrome, which may or may not be effecting things):
I'm on MacOS 10.12.6, Chrome Version 60.0.3112.113 (Official Build) (64-bit).