Download file doesn't seem to work

[ticktoc]

Hi,

I'm having problems downloading recordings via the download button (I can record and delete recordings), when you highlight a recording and click download it displays a blank page with 0 displayed, I've had a look at the adapter.php file and it's at the case md5('download_mp3' . $salt): that is displaying 0. I'm using java8, avconv, also tried ffmpeg with same issue. The rap test page comes back ok, I've checked the config.xml, config.php and all are ok. I can convert the .flv files via command line so avconv works ok.

Moodle 2.7
Ubuntu 14.04
red5 server 1.0.4
apache 2.4.10
php 5.5.12-2
language lab version 2014112600