Topic on Project:Support desk

I've imported this template from Russian Wikipedia. You can see it in an article here. When I fill the "Флаг" (flag) section my page breaks up. I get template html code inside page text:

<th colspan="3" align="center" style="color: white; height: 20px; background: navy;font-size: 110%;">История корабля</th>

I've installed Mediawiki 1.23.1 and ParserFunctions extension. Also I've imported the following css and js files from Russian Wiki: MediaWiki:Common.css, MediaWiki:Common.js, MediaWiki:Vector.css, MediaWiki:Vector.js.

I have problems with many other templates, but in this case I've managed to create a simple example when a template doesn't work.

What am I doing wrong? Did I miss any necessary extensions or scripts?

I think this is the part of code which causes my problem:

{{#if:{{{Флаг|}}}|<th colspan="3" align="center" style="color: white; height: 20px; 
background: navy;font-size: 110%;">'''История корабля'''</th>}}
|-
{{if2cell|[[Государство флага]]|2={{{Флаг}}}}}

This is how it looks in a browser window: