Hi,

Please consider adding an additional check before this loop:

https://github.com/pojome/elementor/blob/59850ebed85c2e1c57cb6f914576677851e7c67d/includes/base/controls-stack.php#L1055

to make sure that $settings[ $control_name ] is not null. This is the case when the repeater field is displayed conditionally in the editor panel. Currently it fires off an "invalid argument supplied" warning in such cases.

Thanks!