Board Thread:Support Requests - Designing Your Wikia/@comment-25386934-20150209205107/@comment-26501002-20150218024624

I see your error. Here is how to make it work, taken directly from the UserTags page:

Installation
To import the script, add the following code to MediaWiki:Common.js: Or add the relevant row to your existing  call if you have one:

You will also need to add the following CSS to MediaWiki:Wikia.css:

And, finally, add this CSS to MediaWiki:Monobook.css:

This is sufficient for the basic functionality; however, if you want to customise it then you will need to read the Configuration section.