PHP Warning 'yii\base\ErrorException' with message 'Undefined variable $groupTag' 

in /usr/local/www/energomeraru/projects/sp/controllers/PressController.php:191

Stack trace:
#0 /usr/local/www/energomeraru/projects/sp/controllers/PressController.php(191): yii\base\ErrorHandler->handleError(2, 'Undefined varia...', '/usr/local/www/...', 191)
#1 [internal function]: projects\sp\controllers\PressController->actionIndex(NULL, 'press', '/press?page=8', 'press')
#2 /usr/local/www/energomeraru/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#3 /usr/local/www/energomeraru/vendor/yiisoft/yii2/base/Controller.php(157): yii\base\InlineAction->runWithParams(Array)
#4 /usr/local/www/energomeraru/vendor/yiisoft/yii2/base/Module.php(528): yii\base\Controller->runAction('index', Array)
#5 /usr/local/www/energomeraru/vendor/yiisoft/yii2/web/Application.php(103): yii\base\Module->runAction('press/index', Array)
#6 /usr/local/www/energomeraru/common/components/Application.php(69): yii\web\Application->handleRequest(Object(common\components\LangRequest))
#7 /usr/local/www/energomeraru/projects/sp/web/index.php(21): common\components\Application->run()
#8 {main}