List page is showing 404

Having the permalink as /%postname%/ it doesn’t work either if I switch back to the original WP theme and disable all plugins. It works though if I change the permalink to the predefined /%year%/%monthnum%/%postname%/ or to a custom /%year%/%postname%/ permalink. From my point of view, it is a WP bug.

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