Categories Menu module breaks the site

www.redzebrafashion.co.uk/shop/
HikaShop Starter: 2.2.3
Joomla! 3.2.1 Stable

I have followed the tutorial on creating a Category list menu module, double checking everything.
However, when I publish the module into my side-bar position, it breaks the site (if you go to the jewellery page, you can see what I mean).
Blank page, no code, nothing. If I unpublish its fine, am I missing something here?

Hi,

If you have a blank page, the best is to activate temporally the debug mode or to change the "error reporting level" to "maximum" in your Joomla global configuration (tab "server").
At this moment you will see the PHP error message and thanks to it, we will be able to fix the problem.

Regards,

No worries fixed it.