Board Thread:Lua Help/@comment-2170536-20150327185855/@comment-4522253-20150327193443

Right. Here's the issue: the tag is actually an extension tag, not Wikitext to be parsed. MediaWiki expects that the output of Lua is effectively ready to render without parsing. You need  frame:extensionTag( name, content, args ). Unfortunately, you don't have it. Wikia's Scribunto backport doesn't yet support it.