Force category-slug.php to show page, even if it doesn’t exist

I’ve not tested this, but adding an action after parse_query or wp which checks if the current request is_category(), and then setting the is_404 property of the global $wp_query to false might set you off in the right direction.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)