problema warning

Ciao,
sono passato dalla versione 7.15 alla 7.17 e ora mi ritrovo con una marea di warning:

Warning: file_get_contents(misc/drupal.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/jquery.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/jquery.once.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.core.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.widget.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.button.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.mouse.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.draggable.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.position.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.resizable.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/ui/jquery.ui.dialog.min.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(modules/system/system.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/form.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(misc/jquery.cookie.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).
Warning: file_get_contents(modules/toolbar/toolbar.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1488 of /web/htdocs/www.psicologacagliari.it/home/includes/locale.inc).

cosa può essere?
grazie