• Navigate to 'Create/Edit User Groups'
• Select a group from the list of configured groups
• Click 'Edit Current user group'
• Click 'Update User Group' button
• Error returned:
  Cannot modify header information - headers already sent by (output started at C:\limesurvey\framework\web\CController.php:794)

C:\limesurvey\application\core\Survey_Common_Action.php(204)

200 // Header
201 if(!isset($aData['display']['header']) || $aData['display']['header'] !== false)
202 {
203 // Send HTTP header
204 header("Content-type: text/html; charset=UTF-8"); // needed for correct UTF-8 encoding
205 Yii::app()->getController()->_getAdminHeader();
206 }