Fatal error: Uncaught Error: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "domestika_excertp_length" not found or invalid function name
in /homepages/38/d236743738/htdocs/clickandbuilds/artene2/wp-includes/class-wp-hook.php on line 303

Call stack:

1. WP_Hook::apply_filters()
   wp-includes/plugin.php:189
2. apply_filters()
   wp-includes/formatting.php:3864
3. wp_trim_excerpt()
   wp-includes/class-wp-hook.php:303
4. WP_Hook::apply_filters()
   wp-includes/plugin.php:189
5. apply_filters()
   wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php:1803
6. WP_REST_Posts_Controller::prepare_item_for_response()
   wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php:550
7. WP_REST_Posts_Controller::get_item()
   wp-includes/rest-api/class-wp-rest-server.php:1146
8. WP_REST_Server::respond_to_request()
   wp-includes/rest-api/class-wp-rest-server.php:993
9. WP_REST_Server::dispatch()
   wp-includes/rest-api/class-wp-rest-server.php:398
10. WP_REST_Server::serve_request()
    wp-includes/rest-api.php:370
11. rest_api_loaded()
    wp-includes/class-wp-hook.php:303
12. WP_Hook::apply_filters()
    wp-includes/class-wp-hook.php:327
13. WP_Hook::do_action()
    wp-includes/plugin.php:518
14. do_action_ref_array()
    wp-includes/class-wp.php:388
15. WP::parse_request()
    wp-includes/class-wp.php:750
16. WP::main()
    wp-includes/functions.php:1291
17. wp()
    wp-blog-header.php:16
18. require()
    index.php:17