Finally worked out the issue, thanks to 'mikew' for referring me to the 'Serving static content' section of the cookbook on CPAN.
What the problem was:
Using the html5 code below I was referencing a simple html page that required no interaction with Catalyst to work.
<p><a href="forgotpassword.html">Forgot Password?</a></p>
However, as mentioned in the Cookbook and Catalyst::Plugin::Static::Simple
"By default, the following extensions are not served (that is, they will be processed by Catalyst): tmpl, tt, tt2, html, xhtml."
and
"There are some file types you may not wish to serve as static files. Most important in this category are your raw template files. By default, files with the extensions tmpl, tt, tt2, html, and xhtml will be ignored by Static::Simple in the interest of security."
To prevent the 'Page not found' error (as the html page is ignored by default) you need to do add the following to the MyApp.pm file ensuring that you remove the extension/s you do not want to be ignored (in my case html files).
MyApp->config(
static => {
ignore_extensions => [
qw/tmpl tt tt2 xhtml/
],
},
);