I tried to install magepal Gmail SMTP pro extension in Magento 2.1.6. when doing manual install thru composer it failed and sad modules required were not present. I therefore deleted all the folders from root folder/var/www/html/app/ which I created. Now when I try to open store>configuration in back end I get exception printing is disabled error I checked the log and find this below can someone advise what I need to do to fix it
a:4:{i:0;s:128:"Notice: Undefined index: id in /var/www/html/vendor/magento/module-config/Model/Config/Structure/Element/Iterator.php on line 59";i:1;s:4941:"#0 /var/www/html/vendor/magento/module-config/Model/Config/Structure/Element/Iterator.php(59): Magento\Framework\App\ErrorHandler->handler(8, 'Undefined index...', '/var/www/html/v...', 59, Array)
#1 /var/www/html/vendor/magento/module-config/Model/Config/Structure.php(92): Magento\Config\Model\Config\Structure\Element\Iterator->setElements(Array, 'default')
#2 /var/www/html/var/generation/Magento/Config/Model/Config/Structure/Interceptor.php(24): Magento\Config\Model\Config\Structure->getTabs()
#3 /var/www/html/vendor/magento/module-config/Model/Config/Structure.php(135): Magento\Config\Model\Config\Structure\Interceptor->getTabs()
#4 /var/www/html/var/generation/Magento/Config/Model/Config/Structure/Interceptor.php(63): Magento\Config\Model\Config\Structure->getFirstSection()
#5 /var/www/html/vendor/magento/module-config/Controller/Adminhtml/System/AbstractConfig.php(57): Magento\Config\Model\Config\Structure\Interceptor->getFirstSection()
#6 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Config\Controller\Adminhtml\System\AbstractConfig->dispatch(Object(Magento\Framework\App\Request\Http))
#7 /var/www/html/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor->___callParent('dispatch', Array)
#8 /var/www/html/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Config\\...', 'dispatch', Object(Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor), Array, 'adminAuthentica...')
#9 /var/www/html/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(143): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
#10 /var/www/html/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#11 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Config\\...', 'dispatch', Object(Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor), Array, 'adminMassaction...')
#12 /var/www/html/vendor/magento/module-backend/App/Action/Plugin/MassactionKey.php(33): Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#13 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#14 /var/www/html/var/generation/Magento/Config/Controller/Adminhtml/System/Config/Index/Interceptor.php(39): Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor->___callPlugins('dispatch', Array, Array)
#15 /var/www/html/vendor/magento/framework/App/FrontController.php(55): Magento\Config\Controller\Adminhtml\System\Config\Index\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#16 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#17 /var/www/html/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#18 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#19 /var/www/html/vendor/magento/framework/Module/Plugin/DbStatusValidator.php(69): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#20 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#21 /var/www/html/var/generation/Magento/Framework/App/FrontController/Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
#22 /var/www/html/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#23 /var/www/html/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
#24 /var/www/html/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#25 {main}";s:3:"url";s:109:"/admin_zedden/admin/system_config/index/key/2166a771bdc0b35669c2a850da41e3b9ecac73d9ced2042ead8395449a105813/";s:11:"script_name";s:10:"/index.php";}
