qTranslate qtrans_convertURL() not working

So I’ve migrated my wordpres site from a development server to the live server and my language switcher doesn’t work anymore. I’m able to run PHP inside a post (ExecPHP plugin) so I know that is not the problem. I’m completely lost. Here is my URL code:

<a href="<?php echo qtrans_convertURL('https://www.dev.jupitercanada.com/?cat=9' .$lang); ?>">Percussion</a>