Same thing that below, you need to define here the variable headerText : 

Rendering Error in layout User/Ban/Form: Property "headerText" is not defined in C:\wamp\www\joomla_3.2.2\components\com_kunena\template\crypsis\layouts\user\ban\form\default.php on line 14
Layout was rendered in C:\wamp\www\joomla_3.2.2\components\com_kunena\template\crypsis\layouts\topic\moderate\default.php on line 145