Fatal error: Uncaught Error: Interface 'Composer\Plugin\PluginInterface' not found in C:\xampp\htdocs\site\wp-content\plugins\blockart-blocks\vendor\composer\installers\src\Composer\Installers\Plugin.php:9 Stack trace: #0 {main} thrown in C:\xampp\htdocs\site\wp-content\plugins\blockart-blocks\vendor\composer\installers\src\Composer\Installers\Plugin.php on line 9