Not load the language pack

Hello @ywtywt,

Thank you for contacting Rank Math support.

We are aware of the issue and working on a solution. Please disable the notice by setting the WP_DEBUG_DISPLAY and WP_DEBUG_LOG constants to false in the wp-config.php file. If you don’t want to do that, please add the following filter to rank-math.php file.

add_filter( 'doing_it_wrong_trigger_error', '__return_false' );

Here is how to create the rank-math.php file: https://rankmath.com/kb/wordpress-hooks-actions-filters/#rank-math-php-file

Hope that helps and please do not hesitate to let us know if you need our assistance with anything else.