Fatal error: Uncaught Error: Interface 'Psr\Container\ContainerInterface' not found in /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor_prefixed/wpdesk/wp-persistence/src/PersistentContainer.php:13 Stack trace: #0 /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor/composer/ClassLoader.php(444): include() #1 /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor/composer/ClassLoader.php(322): Composer\Autoload\includeFile('/usr/www/users/...') #2 [internal function]: Composer\Autoload\ClassLoader->loadClass('FlexibleCoupons...') #3 /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor_prefixed/wpdesk/wp-persistence/src/Adapter/WordPress/WordpressOptionsContainer.php(15): spl_autoload_call('FlexibleCoupons...') #4 /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor/composer/ClassLoader.php(444): include('/usr/www/users/...') #5 /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor/composer/ClassLoader.php(322): Composer\Autoload\includeFile('/usr/www in /usr/www/users/ilgust/wp-content/plugins/flexible-coupons/vendor_prefixed/wpdesk/wp-persistence/src/PersistentContainer.php on line 13