Thread:Project:Support desk/Unable to create a link a a "Main article"

I have an article with a section.

The section itself is a concise form of another full-fledged article.

What I want to do is create a link to the second article.

I am using the tag:

Instead of a link, what I am getting is a red link (to a page that does not exist) saying:

Template:Main

Do I have to install some new extension for this? Or am I getting the code wrong?

NB: This is what I am doing on my own new site. The MediaWiki version is 1.25.1.