Error message

• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in include_once() (line 290 of sites/sicherheitskonferenz.de/settings.php).
• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in include_once() (line 291 of sites/sicherheitskonferenz.de/settings.php).
• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in include_once() (line 299 of sites/sicherheitskonferenz.de/settings.php).
• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in include_once() (line 306 of sites/sicherheitskonferenz.de/settings.php).
• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in drupal_settings_initialize() (line 829 of includes/bootstrap.inc).
• Warning: ini_set(): Headers already sent. You cannot change the session module's ini settings at this time in drupal_settings_initialize() (line 838 of includes/bootstrap.inc).
• Warning: session_name(): Cannot change session name when headers already sent in drupal_settings_initialize() (line 841 of includes/bootstrap.inc).