An error has happened during application run. See exception log for details.

[DAWS96]

Hi everyone,

I have recently changed my PHP version from 7.0 to 7.2 and I am now seeing the following error message on the admin login screen, can anyone help?

Exception: Warning: Use of undefined constant MCRYPT_RIJNDAEL_256 - assumed 'MCRYPT_RIJNDAEL_256' (this will throw an Error in a future version of PHP) in /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/Encryption/Encryptor.php on line 394 in /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/App/ErrorHandler.php:61 Stack trace: #0 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/Encryption/Encryptor.php(394): Magento\Framework\App\ErrorHandler->handler(2, 'Use of undefine...', '/home/sites/7a/...', 394, Array) #1 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/Encryption/Encryptor.php(313): Magento\Framework\Encryption\Encryptor->getCrypt('26d218c8df20ce4...', 2, 'ofa9FHQoP6seYsG...') #2 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/Serialize/Serializer/Sensitive.php(59): Magento\Framework\Encryption\Encryptor->decrypt('h+hjAyBAVnqbbld...') #3 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/module-config/App/Config/Type/System.php(235): Magento\Framework\Serialize\Serializer\Sensitive->unserialize('0:2:ofa9FHQoP6s...') #4 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/module-config/App/Config/Type/System.php(171): Magento\Config\App\Config\Type\System->loadScopeData('stores', 'default') #5 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/App/Config.php(131): Magento\Config\App\Config\Type\System->get('stores/default/...') #6 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/App/Config.php(80): Magento\Framework\App\Config->get('system', 'stores/default/...') #7 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/module-developer/Model/Logger/Handler/Debug.php(63): Magento\Framework\App\Config->getValue('dev/debug/debug...', 'stores') #8 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/monolog/monolog/src/Monolog/Handler/AbstractProcessingHandler.php(29): Magento\Developer\Model\Logger\Handler\Debug->isHandling(Array) #9 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/monolog/monolog/src/Monolog/Logger.php(337): Monolog\Handler\AbstractProcessingHandler->handle(Array) #10 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/Logger/Monolog.php(48): Monolog\Logger->addRecord(400, 'Warning: Use of...', Array) #11 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/monolog/monolog/src/Monolog/Logger.php(616): Magento\Framework\Logger\Monolog->addRecord(400, 'Warning: Use of...', Array) #12 /home/sites/7a/0/0fb5369a30/public_html/magento/vendor/magento/framework/App/Bootstrap.php(262): Monolog\Logger->error('Warning: Use of...') #13 /home/sites/7a/0/0fb5369a30/public_html/magento/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor)) #14 {main}

Kind regards,

Dan

[Tarandeep Singh]

@DAWS96What version of Magento you are on? PHP 7.2 is supported on 2.3. If you are on compatible version then you might be missing a PHP module which can be install/configure by using below links.

https://magento.stackexchange.com/questions/240580/use-of-undefined-constant-mcrypt-rijndael-256-ass...

https://stackoverflow.com/questions/29993399/use-of-undefined-constant-mcrypt-rijndael-128-assumed-m...

Problem solved? Please give 'Kudos' and accept 'Answer as Solution'.

[HitsVaghasiya]

Hello @DAWS96 

Please check the "mcrypt" PHP extension.

As you have update new PHP version it will affect this.

if not install please install "mcrypt" and Run the below command.

php bin/magento setup:upgrade
php bin/magento indexer:reindex
php bin/magento cache:flush
php bin/magento cache:clean
php bin/magento setup:static-content:deploy -f