Backtrace:

... (Array, 10 elements)
 9: swftools_admin_players_options() (Array, 2 elements)
file (String, 58 characters ) sites/all/modules/swftools/includes/swftools.ad...
args (Array, 3 elements)
0 (String, 5 characters ) audio
1 (String, 19 characters ) A single audio file
2 (String, 0 characters )
 8: swftools_players_profile_form() (Array, 2 elements)
 7: swftools_admin_players_form() (Array, 2 elements)
 6: call_user_func_array() (Array, 1 element)
 5: drupal_retrieve_form() (Array, 2 elements)
 4: drupal_build_form() (Array, 2 elements)
 3: drupal_get_form() (Array, 2 elements)
 2: call_user_func_array() (Array, 1 element)
 1: menu_execute_active_handler() (Array, 2 elements)
 0: main() (Array, 2 elements)