Thread:Extension talk:WYSIWYG/IE11 with MW 1.22.0 + WYSIWYG extension: Existing category definitions will corrupt after after page has been saved/reply (5)

This extension is very buggy, and every bugfix appears to uncover new problems :(

I'm seriously thinking of closing the documentation page and directing users to VisualEditor (perhaps buggier than WYSIWYG, but newer).