Thread:Extension talk:WYSIWYG/IE11 with MW 1.22.0 + WYSIWYG extension: Existing category definitions will corrupt after after page has been saved/reply (12)

I think I have already done this kind of modification because of this empty_page problem. Definition is currently in file /includes/OutputPage.php like this (NOTE! File is not included in #6 bundle):

Modified setting helped to solve the empty page problem with bulleted and numbered lists on save with IE11 browser earlier. I do not remember why setting "IE=9" was selected, because any one of the values 8, 9, 10 or Edge would have done the trick in that case.