diff --git a/lam/lib/modules.inc b/lam/lib/modules.inc
index a427146a..66430c6d 100644
--- a/lam/lib/modules.inc
+++ b/lam/lib/modules.inc
@@ -1433,6 +1433,7 @@ class accountContainer {
 		foreach ($module as $singlemodule) {
 			// load changes
 			$temp = $this->module[$singlemodule]->save_attributes();
+			if (!is_array($temp)) $temp = array();
 			// merge changes
 			$DNs = array_keys($temp);
 			// *** fixme don't include references
diff --git a/lam/lib/modules/posixGroup.inc b/lam/lib/modules/posixGroup.inc
index b9139c54..f1dfcb20 100644
--- a/lam/lib/modules/posixGroup.inc
+++ b/lam/lib/modules/posixGroup.inc
@@ -579,7 +579,7 @@ class posixGroup extends baseModule {
 			$maxID = intval($this->moduleSettings['posixGroup_maxGID'][0]);
 			$dn_gids = $_SESSION['cache']->get_cache('gidNumber', 'posixGroup', 'group');
 			// get_cache will return an array ( dn1 => array(uidnumber1), dn2 => array(uidnumber2), ... )
-			if(is_array($dn_gids)) {
+			if(is_array($dn_gids) && (sizeof($dn_gids) > 0)) {
 				foreach ($dn_gids as $gid) $gids[] = $gid[0];
 				sort ($gids, SORT_NUMERIC);
 			}