500 : Erreur interne au serveur

array_key_exists() expects parameter 2 to be array, null given

Une erreur interne est survenue quand le serveur Web traitait votre requête.
Veuillez contacter Administrateur pour rapporter ce problème.
                    #0 /var/www/html/limesurvey-4.0.0/application/core/LSETwigViewRenderer.php(719): array_key_exists()
#1 /var/www/html/limesurvey-4.0.0/application/core/LSETwigViewRenderer.php(698): LSETwigViewRenderer->fixDataCoherence()
#2 /var/www/html/limesurvey-4.0.0/application/core/LSETwigViewRenderer.php(767): LSETwigViewRenderer->getAdditionalInfos()
#3 /var/www/html/limesurvey-4.0.0/application/helpers/expressions/em_manager_helper.php(6672): LSETwigViewRenderer->renderPartial()
#4 /var/www/html/limesurvey-4.0.0/application/helpers/expressions/em_manager_helper.php(6114): LimeExpressionManager->_ValidateQuestion()
#5 /var/www/html/limesurvey-4.0.0/application/helpers/expressions/em_manager_helper.php(6012): LimeExpressionManager->_ValidateGroup()
#6 /var/www/html/limesurvey-4.0.0/application/helpers/expressions/em_manager_helper.php(5751): LimeExpressionManager->_ValidateSurvey()
#7 /var/www/html/limesurvey-4.0.0/application/helpers/SurveyRuntimeHelper.php(793): JumpTo()
#8 /var/www/html/limesurvey-4.0.0/application/helpers/SurveyRuntimeHelper.php(646): SurveyRuntimeHelper->initFirstStep()
#9 /var/www/html/limesurvey-4.0.0/application/helpers/SurveyRuntimeHelper.php(204): SurveyRuntimeHelper->initMove()
#10 /var/www/html/limesurvey-4.0.0/application/controllers/survey/index.php(604): SurveyRuntimeHelper->run()
#11 /var/www/html/limesurvey-4.0.0/application/controllers/survey/index.php(24): index->action()
#12 /var/www/html/limesurvey-4.0.0/framework/web/actions/CAction.php(76): index->run()
#13 /var/www/html/limesurvey-4.0.0/framework/web/CController.php(308): index->runWithParams()
#14 /var/www/html/limesurvey-4.0.0/framework/web/CController.php(286): SurveyController->runAction()
#15 /var/www/html/limesurvey-4.0.0/framework/web/CController.php(265): SurveyController->runActionWithFilters()
#16 /var/www/html/limesurvey-4.0.0/framework/web/CWebApplication.php(282): SurveyController->run()
#17 /var/www/html/limesurvey-4.0.0/framework/web/CWebApplication.php(141): LSYii_Application->runController()
#18 /var/www/html/limesurvey-4.0.0/framework/base/CApplication.php(185): LSYii_Application->processRequest()
#19 /var/www/html/limesurvey-4.0.0/index.php(195): LSYii_Application->run()