Fatal error: Uncaught Error: Class 'Composer\Installers\BaseInstaller' not found in C:\xampp\htdocs\site\wp-content\plugins\blockart-blocks\vendor\composer\installers\src\Composer\Installers\ItopInstaller.php:4 Stack trace: #0 {main} thrown in C:\xampp\htdocs\site\wp-content\plugins\blockart-blocks\vendor\composer\installers\src\Composer\Installers\ItopInstaller.php on line 4