When we change the language of the site while trying to add an event to our website, a 404 error message appears. However, this issue is now fixed with a simple code that needs to be pasted in the function.php. Now the error message does not appear while adding an event after changing the language. Or you can create a child theme and paste the code in the child theme’s function.php
Here is the code
add_action('init',function() {if(is_admin()) {return;}$current_locale= get_locale();$flushed_locale= get_option('last_flushed_locale');if($current_locale!==$flushed_locale) {flush_rewrite_rules(false);update_option('last_flushed_locale',$current_locale);}});