Magento 2 - while saving product from admin getting error as Class Magento\ConfigurableProduct\Model\Product\VariationHandler does not exist

Question

Magento 2 while saving product from admin getting error as "Class Magento\ConfigurableProduct\Model\Product\VariationHandler does not exist". But this class is there in Vendor folder.

There is no use even after clearing generation files and re-compiling the code.

Answer 1

This is a strange issue.

Override getConstructor method in vendor/magento/framework/Code/Reader/ClassReader.php and change it to below

public function getConstructor($className)
{
    $class = new \ReflectionClass($className);
    $result = null;
    $constructor = $class->getConstructor();
    if ($constructor) {
        $result = [];
        /** @var $parameter \ReflectionParameter */
        foreach ($constructor->getParameters() as $parameter) {
            try {
                $result[] = [
                    $parameter->getName(),
                    $parameter->getClass() !== null ? $parameter->getClass()->getName() : null,
                    !$parameter->isOptional(),
                    $parameter->isOptional()
                        ? ($parameter->isDefaultValueAvailable() ? $parameter->getDefaultValue() : null)
                        : null,
                ];
            } catch (\ReflectionException $e) {
            if($parameter->getName() == 'variationHandler' ) {
                $result[] = [
                        $parameter->getName(),
                        $parameter->getClass() !== null ? $parameter->getClass()->getName() : null,
                        !$parameter->isOptional(),
                        $parameter->isOptional()
                            ? ($parameter->isDefaultValueAvailable() ? $parameter->getDefaultValue() : null)
                            : null,
                    ];
                    continue;
            }
                $message = $e->getMessage();
                throw new \ReflectionException($message, 0, $e);
            }
        }
    }

    return $result;
}