testlink crash down when adding a new type of results

1.   Add  a  new type of Test results on execution page
  -------<> P36 0f  total 57

 the opration of custom_config.inc.php  file which created  by users causes crashdown of the TL

2.  ../cfg/const.inc.php:
 
$tlCfg->results['status_label'] = array(
445        'not_run'       => 'test_status_not_run',
446         'passed'        => 'test_status_passed',
447         'failed'        => 'test_status_failed',
448         'blocked'       => 'test_status_blocked'
449 //      'all'           => 'test_status_all_status',
450 //      'not_available' => 'test_status_not_available',
451 //      'unknown'       => 'test_status_unknown'
452 );

 sentences from  449  to  451  can't be changed
 
 why?   all  changes like this will cause crashdown