`window.openerp` being undefined, the method `on_modules_loaded` throws an error when reaching its purpose (loading additional modules)... The commit odoo/odoo@905e01921f removed the compatibility layer for Odoo v8 (compatibility.js) which contained the `window.openerp` declaration. Being broken for that long without consequences, this feature proved to not be useful anymore. We then remove it. closes odoo/odoo#34821 Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>