Got a small problem with a custom plugin that was created

Hi guys,

Got a small problem with a custom plugin that was created for me - which worked fine before 2 things:
1) a wordpress updgrade
2) a plugin upgrade (LearnDash LMS)

I can't figure out which one is causing the issue, however, the problem I'm now left with is that the shortcode is not rendering - as seen here:
http://demo.xlearn.net.au/learning/my-training/

The shortcode is just a 1 file plugin called:
/wp-content/plugins/sf3_learndash_shortcodes/sf3_learndash_shortcodes.php

The shortcode is supposed to output a list of courses that meet certain criteria (e.g. pending / in progress / completed)

Any tips on what might be causing this issue would be great.

Thanks!
Brett