mhtml displayed as plain text in browser

Question

I am quite new to Perl and Mason. Please excuse me if you think my question here is trivial.

There is a website that has been developed using the Mason framework. As per my knowledge, it only uses Apache, Perl (ModPerl), Mason and MySQL. I have the website's code with me and I am trying to make the website work on my Ubuntu localhost.

These are the steps that I followed from scratch:

1. Installed Apache, MySQL, Perl and ModPerl
2. Installed HTML-Mason with cpanm: cpanm HTML::Mason
3. Added the following lines to apache.conf

AddType text/html .mhtml

PerlSetVar MasonCompRoot /var/www/comps
PerlSetVar MasonDataDir /var/mason-data-dir
PerlModule HTML::Mason::ApacheHandler

<LocationMatch "\.mthml$">
    SetHandler perl-script
    PerlHandler HTML::Mason::ApacheHandler
</LocationMatch>

<LocationMatch "(.mas|handler)$">
    SetHandler perl-script
    PerlHandler "sub { return Apache::Constants::NOT_FOUND }"
</LocationMatch>

I am testing like this

I created a simple "Hello World" file named test.mhtml and placed it in the directory /var/www/. When I try to open this file in the browser it displays the following:

% my $var = "World"; Hello <%$var%>

instead of displaying just Hello World

Do I have to make any other configuration changes?