I always have browsed my courses with IE, but some of my students prefer use the Mozilla to navegate through the different modules of my courses and then they have problems, like missing audio, error messages, and so on. How to configure out the Mozilla browser to view my courses correctly?. Or how to configure CourseLab to use Mozilla as my browser?  

on the opening page make a block of text in large bold characters..
Advisory notice
This course material works best with IE, full functionality is NOT available on other web browsers.
You can't change the browser to accomodate this and it is not easy to fix all of the problems in courselab 2.4. It is unfortunately the way it is.
If you need to make more compatible courses you could try the new 2.7 version