Magento 2 - "Class does not exist" when I click checkout button

Question

Customer can not reach checkout page because there is error message "Class does not exist"

So i checked error log. the log shows below message. I do not know what to do.

This is magento 2.2.2.

Please let me know how to solve

{"0":"Class does not exist","1":"#0 /home/mg222/public_html/vendor/magento/framework/Code/Reader/ClassReader.php(19): ReflectionClass->__construct('')\n#1 /home/mg222/public_html/vendor/magento/framework/ObjectManager/Definition/Runtime.php(44): Magento\Framework\Code\Reader\ClassReader->getConstructor('')\n#2 /home/mg222/public_html/vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php(48): Magento\Framework\ObjectManager\Definition\Runtime->getParameters('')\n#3 /home/mg222/public_html/vendor/magento/framework/ObjectManager/ObjectManager.php(56): Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create('', Array)\n#4 /home/mg222/public_html/generated/code/Magento/Customer/Model/AddressFactory.php(57): Magento\Framework\ObjectManager\ObjectManager->create(NULL, Array)\n#5 /home/mg222/public_html/vendor/magento/module-customer/Model/AddressRegistry.php(46): Magento\Customer\Model\AddressFactory->create()\n#6 /home/mg222/public_html/vendor/magento/module-customer/Model/ResourceModel/AddressRepository.php(166): Magento\Customer\Model\AddressRegistry->retrieve('100389')\n#7 /home/mg222/public_html/vendor/magento/module-quote/Model/Quote.php(936): Magento\Customer\Model\ResourceModel\AddressRepository->getById('100389')\n#8 /home/mg222/public_html/vendor/magento/module-quote/Model/Quote.php(913): Magento\Quote\Model\Quote->assignCustomerWithAddressChange(Object(Magento\Customer\Model\Data\Customer))\n#9 /home/mg222/public_html/vendor/magento/module-checkout/Model/Type/Onepage.php(339): Magento\Quote\Model\Quote->assignCustomer(Object(Magento\Customer\Model\Data\Customer))\n#10 /home/mg222/public_html/generated/code/Magento/Checkout/Model/Type/Onepage/Interceptor.php(76): Magento\Checkout\Model\Type\Onepage->initCheckout()\n#11 /home/mg222/public_html/vendor/magento/module-checkout/Controller/Index/Index.php(37): Magento\Checkout\Model\Type\Onepage\Interceptor->initCheckout()\n#12 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(60): Magento\Checkout\Controller\Index\Index->execute()\n#13 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(174): Magento\Checkout\Controller\Index\Index\Interceptor->___callParent('execute', Array)\n#14 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(189): Magento\Checkout\Controller\Index\Index\Interceptor->Magento\Framework\Interception\{closure}()\n#15 /home/mg222/public_html/generated/code/Magento/Checkout/Controller/Index/Index/Interceptor.php(26): Magento\Checkout\Controller\Index\Index\Interceptor->___callPlugins('execute', Array, Array)\n#16 /home/mg222/public_html/vendor/magento/framework/App/Action/Action.php(107): Magento\Checkout\Controller\Index\Index\Interceptor->execute()\n#17 /home/mg222/public_html/vendor/magento/module-checkout/Controller/Onepage.php(161): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))\n#18 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(60): Magento\Checkout\Controller\Onepage->dispatch(Object(Magento\Framework\App\Request\Http))\n#19 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(174): Magento\Checkout\Controller\Index\Index\Interceptor->___callParent('dispatch', Array)\n#20 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(189): Magento\Checkout\Controller\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))\n#21 /home/mg222/public_html/generated/code/Magento/Checkout/Controller/Index/Index/Interceptor.php(39): Magento\Checkout\Controller\Index\Index\Interceptor->___callPlugins('dispatch', Array, Array)\n#22 /home/mg222/public_html/vendor/magento/framework/App/FrontController.php(55): Magento\Checkout\Controller\Index\Index\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))\n#23 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(60): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))\n#24 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(174): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)\n#25 /home/mg222/public_html/vendor/magento/module-store/App/FrontController/Plugin/RequestPreprocessor.php(94): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))\n#26 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(171): Magento\Store\App\FrontController\Plugin\RequestPreprocessor->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))\n#27 /home/mg222/public_html/vendor/magento/module-page-cache/Model/App/FrontController/BuiltinPlugin.php(73): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))\n#28 /home/mg222/public_html/app/code/TemplateMonster/SiteMaintenance/Model/PageCache/App/FrontController/BuiltinPlugin.php(30): Magento\PageCache\Model\App\FrontController\BuiltinPlugin->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))\n#29 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(171): TemplateMonster\SiteMaintenance\Model\PageCache\App\FrontController\BuiltinPlugin->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))\n#30 /home/mg222/public_html/vendor/magento/framework/Interception/Interceptor.php(189): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))\n#31 /home/mg222/public_html/generated/code/Magento/Framework/App/FrontController/Interceptor.php(29): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, NULL)\n#32 /home/mg222/public_html/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))\n#33 /home/mg222/public_html/generated/code/Magento/Framework/App/Http/Interceptor.php(24): Magento\Framework\App\Http->launch()\n#34 /home/mg222/public_html/vendor/magento/framework/App/Bootstrap.php(256): Magento\Framework\App\Http\Interceptor->launch()\n#35 /home/mg222/public_html/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))\n#36 {main}","url":"/checkout/","script_name":"/index.php"}

Answer 1

Hello please run following command and retry

php bin/magento setup:upgrade

php bin/magento setup:di:compile

php bin/magento setup:static-content:Deploy -f

chmod -R 777 var/ generated/