Board Thread:General Discussion/@comment-36292318-20180723145358/@comment-9605025-20180723161229

Comments are only placed on blogs (pages in the "User_blog" namespace) and articles (pages in the "(Main)" namespace). Right now, it looks like all you have is the wiki's main page; which doesn't count. Also, when you say "Discussions", do you mean the thing at the bottom of the articles (between the bottom of the article content and before the comment section; described here) or the feature already available from your wikis navigation bar (described here)? Based on the context of your question, I am guessing you are asking about the former. In that case, you cannot enable them. They are part of a old extension that is being phased out by the latter.