$url = 'modules.php?module=index';
// Check for determined referal id
-if ((isReferalIdValid()) && (isValidUserId(determineReferalId()))) {
+if ((isExtensionActive('user')) && (isReferalIdValid()) && (isValidUserId(determineReferalId()))) {
// Update ref counter
SQL_QUERY_ESC("UPDATE `{?_MYSQL_PREFIX?}_user_data` SET `ref_clicks`=`ref_clicks`+1 WHERE `userid`=%s LIMIT 1",
array(makeDatabaseUserId(determineReferalId())), __FILE__, __LINE__);