strange error message

Warning: main(../wp-includes/wp-l10n.php): failed to open stream: No such file or directory in /home/dailyfal/public_html/wp-admin/post.php on line 4
Fatal error: main(): Failed opening required ‘../wp-includes/wp-l10n.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/dailyfal/public_html/wp-admin/post.php on line 4
Anyone know what it means? I attempted to upgrade from 1.0 to 1.2. Perhaps the upgrade did not go well. This error occurs when I attempt to log in.