Fatal error: Uncaught Error: Interface "Composer\Plugin\PluginInterface" not found in C:\Apache24\htdocs\cms_upgrade\vendor\composer\installers\src\Composer\Installers\Plugin.php:9
Stack trace:
#0 {main}
thrown in C:\Apache24\htdocs\cms_upgrade\vendor\composer\installers\src\Composer\Installers\Plugin.php on line 9