Just for info: If User Groups are disabled in the buddypress settings, the activation of the plugin results in
Fatal error: Class 'BP_Group_Extension' not found in wp-content/plugins/buddypress-media/includes/bp-media-groups-loader.php on line 5
Hi Hugo,
We noticed this error a few days ago. We have taken care of this bug in our development and will release an updated version in the first week of the new year.
If it is not a huge convenience, activating groups will fix this, temporarily.
Regards,