count(): Parameter must be an array or an object that implements Countable

Hello

I am getting these errors in query monitor:

do_action(‘tools_page_custom-slug-language’)
wp-admin/admin.php:253
crrq_language_page_callback()
wp-includes/class-wp-hook.php:286
wp-content/plugins/wp-slug-post-type-custom-language/inc/list-custom-slug-language.php:74
Plugin: wp-slug-post-type-custom-language
Warning count(): Parameter must be an array or an object that implements Countable 1
+
wp-content/plugins/wp-slug-post-type-custom-language/inc/list-custom-slug-language.php:80