Issue: ErrorException: Undefined index: smilie - vault\core\model\parser\instance\xf.php:128

Server Error Log
Error Info
ErrorException: Undefined index: smilie - vault\core\model\parser\instance\xf.php:128
Generated By: Nic, Today at 14:40
Stack Trace
#0 D:\inetpub\wwwroot\domain.com\vault\core\model\parser\instance\xf.php(128): XenForo_Application::handlePhpError(8, 'Undefined index...', 'D:\\inetpub\\wwwr...', 128, Array)
#1 D:\inetpub\wwwroot\domain.com\vault\core\model\parser\instance\vw.php(271): vw_Parser_Instance_Model_XF->parse(Array)
#2 D:\inetpub\wwwroot\domain.com\vault\core\model\parser\instance\xf.php(222): vw_Parser_Instance_Model->get_preview(Array, 0)
#3 D:\inetpub\wwwroot\domain.com\vault\core\controller\ui\page\vw.php(840): vw_Parser_Instance_Model_XF->get_preview(Array, 0)
#4 D:\inetpub\wwwroot\domain.com\vault\core\controller\ui\stack\vw.php(343): vw_UI_Page_Controller->preview()
#5 D:\inetpub\wwwroot\domain.com\vault\core\controller\ui\ajax\preview\vw.php(69): vw_UI_Stack_Controller->preview()
#6 D:\inetpub\wwwroot\domain.com\library\vw\XenForo\ControllerPublic\Wiki\Ajax.php(50): vw_UI_AJAX_Preview_Controller->execute()
#7 D:\inetpub\wwwroot\domain.com\library\XenForo\FrontController.php(369): vw_XenForo_ControllerPublic_Wiki_Ajax->actionIndex()
#8 D:\inetpub\wwwroot\domain.com\library\XenForo\FrontController.php(152): XenForo_FrontController->dispatch(Object(XenForo_RouteMatch))
#9 D:\inetpub\wwwroot\domain.com\index.php(13): XenForo_FrontController->run()
#10 {main}
Request State
array(3) {
  ["url"] => string(67) "https://domain.com/index.php?wiki-ajax/&c=preview"
  ["_GET"] => array(2) {
    ["wiki-ajax/"] => string(0) ""
    ["c"] => string(7) "preview"
  }
  ["_POST"] => array(5) {
    ["ajax"] => int(1)
    ["target"] => string(4) "akku"
    ["prefixid"] => string(1) "0"
    ["_xfToken"] => string(8) "********"
    ["c"] => string(7) "preview"
  }
}