This is a common error while upgrading Magento 2.x To Magento 2.4.3
Deprecated Functionality: Class Laminas\Hydrator\Reflection is deprecated, please use Laminas\Hydrator\ReflectionHydrator instead in /pathToMagento/web/vendor/laminas/laminas-hydrator/src/Reflection.php on line 17
The following below solution
Solution [1] – After Upgrade Magento 2.x To Magento 2.4.3
Once you successfully upgraded Magento 2.x To Magento 2.4.3 and issue occurs as above-mentioned.
The laminas class might be used in some of the extensions, need to update the specific code of these extensions.
Using below command we can find which extensions, using laminas class.
grep -r 'class to search' app/
Solution [2] – Before Upgrade Magento 2.x To Magento 2.4.3
Copy below code from Magento 2.4.3 & Paste in Magento 2.x
"require-dev": {
"allure-framework/allure-phpunit": "~1.2.0",
"dealerdirect/phpcodesniffer-composer-installer": "^0.5.0",
"friendsofphp/php-cs-fixer": "~2.16.0",
"lusitanian/oauth": "~0.8.10",
"magento/magento-coding-standard": "*",
"magento/magento2-functional-testing-framework": "^3.0",
"pdepend/pdepend": "~2.7.1",
"phpcompatibility/php-compatibility": "^9.3",
"phpmd/phpmd": "^2.8.0",
"phpstan/phpstan": ">=0.12.3 <=0.12.23",
"phpunit/phpunit": "^9",
"sebastian/phpcpd": "~5.0.0",
"squizlabs/php_codesniffer": "~3.5.4"
},After paste above code in Magento 2.x, start upgrade process.
Other important Magento 2.4.x issue as below
Magento 2.3 To Magento 2.4.5 Comptibility For PHP, MYSQL, Composer, Apache etc
Magento 2.4.3-p1 Installation Steps
Magento 2.4.3 Installation Steps
Magento 2.4 Two Factor Authentication
Magento 2.2, Magento 2.3, Magento2.4 Installation Issue on Windows 10, XAMPP
Magento 2 Installation at 51% Error: (Wrong file in Gd2.php:64) Module ‘Magento_Theme’