500: Internal Server Error

Undefined variable: chek

An internal error occurred while the Web server was processing your request.

Please contact Administrator to report this problem.

                    #0 unknown(0): brokenBeforeSurvey->beforeSurveyPage()
#1 /mnt/data/shnoulle/nginx/www/master/application/libraries/PluginManager/PluginManager.php(258): call_user_func()
#2 /mnt/data/shnoulle/nginx/www/master/application/controllers/survey/index.php(171): LimeSurvey\PluginManager\PluginManager->dispatchEvent()
#3 /mnt/data/shnoulle/nginx/www/master/application/controllers/survey/index.php(24): index->action()
#4 /mnt/data/shnoulle/nginx/www/master/framework/web/actions/CAction.php(76): index->run()
#5 /mnt/data/shnoulle/nginx/www/master/framework/web/CController.php(308): index->runWithParams()
#6 /mnt/data/shnoulle/nginx/www/master/framework/web/CController.php(286): SurveyController->runAction()
#7 /mnt/data/shnoulle/nginx/www/master/framework/web/CController.php(265): SurveyController->runActionWithFilters()
#8 /mnt/data/shnoulle/nginx/www/master/framework/web/CWebApplication.php(282): SurveyController->run()
#9 /mnt/data/shnoulle/nginx/www/master/framework/web/CWebApplication.php(141): LSYii_Application->runController()
#10 /mnt/data/shnoulle/nginx/www/master/framework/base/CApplication.php(185): LSYii_Application->processRequest()
#11 /mnt/data/shnoulle/nginx/www/master/index.php(195): LSYii_Application->run()