Thread:Extension talk:WYSIWYG/1.18 and User made (experimental), ie8 problem with lists/reply (6)

Thanks for pointing it out. I never noticed it but i got the reason for this Category remove issue. A few lines of code got removed while the patch from thread Patch for MW 1.19. So, you can add these lines inside parse function or replace parse function in CKeditorParser.body.php.

Thanks once again for finding this bug.