construct called incorrectly

When I enable kirki in my paid theme (fotomag), post cover images are displayed out of proportion (the console reads “jQuery is not compatible with Quirks Mode”).
I enabled wp-debugging and get this error messsage:

Notice: Kirki_Field::__construct was called incorrectly. Config not defined for field fotomag_set_extras_pagination – See https://aristath.github.io/kirki/docs/getting-started/fields.html for details on how to properly add fields. Please see Debugging in WordPress for more information. (This message was added in version 3.0.10.) in /html/wp-includes/functions.php on line 4147

I’m running wp4.9.5, nginx & php7.2