Fatal error: Uncaught Twig_Error_Runtime: Impossible to access an attribute ("name") on a null variable. in /data/wwwroot/xueyuan/xueyuan/plugins/VipPlugin/Resources/views/Slot/course-purchase-extension-slot.html.twig:7 Stack trace: #0 /data/wwwroot/xueyuan/xueyuan/app/cache/prod/Zero/classes.php(3308) : eval()'d code(42): Twig_Template->getAttribute(NULL, 'name', Array) #1 /data/wwwroot/xueyuan/xueyuan/app/cache/prod/Zero/classes.php(5146): __TwigTemplate_888029ab34e3887127028c0f1976c52d5c545098a428f63f13996d79de45a1ab->doDisplay(Array, Array) #2 /data/wwwroot/xueyuan/xueyuan/app/cache/prod/Zero/classes.php(5122): Twig_Template->displayWithErrorHandling(Array, Array) #3 /data/wwwroot/xueyuan/xueyuan/app/cache/prod/Zero/classes.php(5129): Twig_Template->display(Array) #4 /data/wwwroot/xueyuan/xueyuan/app/cache/prod/Zero/classes.php(3259): Twig_Template->render(Array) #5 /data/wwwroot/xueyuan/xueyuan/plugins/VipPlugin/Slot/CoursePurchaseExtensionSlot.php(37): Twig_Environment->render('VipPlugin:Slot:...', Array) #6 /data/w in /data/wwwroot/xueyuan/xueyuan/vendor/twig/twig/lib/Twig/Loader/Chain.php on line 129