i'm trying to troubleshoot a Drupal 6.16 site that I did not build -- so I'm not entirely clear on its install history. if a new Page node is created -- nothing fancy, just text content -- @ nav to that page, i frequently see the following errors: * warning: array_keys() expects parameter 1 to be array, null given in /srv/www/id/0323/includes/common.inc on line 1865. * warning: Invalid argument supplied for foreach() in /srv/www/id/0323/includes/common.inc on line 1865. that's frequently -- but not always. i haven't been able to determine what conditions cause the error to fire. most often, simply refreshing the page makes the error disappear. the error's rather generic -- and not reliably reproducible ... looking @ lineno 1865 in common.inc, ------------------------- foreach ($css as $media => $types) { // If CSS preprocessing is off, we still need to output the styles. // Additionally, go through any remaining styles if CSS preprocessing is on and output the non-cached ones. foreach ($types as $type => $files) { if ($type == 'module') { // Setup theme overrides for module styles. $theme_styles = array(); 1865: foreach (array_keys($css[$media]['theme']) as $theme_style) { $theme_styles[] = basename($theme_style); } ------------------------- nothing immediately jumps out at me as to specific cause :-/ other than hunt-n-peck, how can I narrow down what's causing this? any suggestions appreciated! BenDJ