Fatal error: Uncaught Error: Interface "IWPML_Upgrade_Command" not found in /home/oxygenco/prod/wordpress/wp-content/plugins/sitepress-multilingual-cms/classes/upgrade/commands/abstracts/class-wpml-upgrade-add-column-to-table.php:11 Stack trace: #0 {main} thrown in /home/oxygenco/prod/wordpress/wp-content/plugins/sitepress-multilingual-cms/classes/upgrade/commands/abstracts/class-wpml-upgrade-add-column-to-table.php on line 11