arrow function used for error handler and error function is defined inside inner function so this will get changed, need to use self, also arrow function doesn't have its own arguments object, https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions Issue raised from following commit: https://github.com/odoo/odoo/commit/2d6dc75a2cb5fa81189920d0f7fdc7b7f12132ab task-2052484 closes odoo/odoo#35788 Signed-off-by: pimodoo <pimodoo@users.noreply.github.com>