Thread:Extension talk:WYSIWYG/IE11 with MW 1.22.0 + WYSIWYG extension: Existing category definitions will corrupt after after page has been saved/reply (8)

I have tested this fix (and #6 bundle) with IE8, IE11, FireFox (v26.0, v27.0) and Chrome(32.0.1700.102 m): with these browsers wysiwyg of #6 bundle works ok (with the modification you suggested).

With IE11 I have not noticed before that I have on page "Tools=>Compatibility View settings" selected option "Display intranet sites in compatibility view". With this setting on (#6 bundle of) wysiwyg works ok. If I deselect that setting, wysiwyg eiditor won't start and it reverts to wikieditor.