I have developed a course using CourseLab 2.4. I have a problem of not being able to play MP3 sound files in Firefox. I am getting a javascript error "oPlayer.controls is undefined". I am using the "Sound" tab on the "Format Object" popup window to define the sound file associated with an object.

Did anyone encounter such a problem.

Thanks in advance.

Maybe (probably) CL is using the windows mediaplayer which is not by default a plugin in Firefox.
Either install the plugin (but all your students must also install it) or use a flash player.
The Flash plugin is installed in most browsers.[:)]