Board Thread:Support Requests - Getting Technical/@comment-3147293-20161202081742

AFAIK users can add styles/scrpits just for themselves using Special:MyPage/global.css and/or Special:MyPage/global.js. However, mine has absolutely no effect on any of Wikia. What am I doing wrong with this? Am I not on the right page to put the script, or did I do some mistakes while importing? Thank you for sharing your experience and advice. 