Board Thread:Support Requests - Community Management/@comment-97.102.137.118-20130311220619/@comment-856287-20140524055639

You can turn it on or off in Special:WikiFeatures (but you've already turned it off for team-quatre-knights). You may also have set it for yourself in your user preferences under Editing → Preferred Editor.

Even if it's turned on, you can use the Edit button's drop-down menu to select "Classic editor."