子域为yii提供500内部服务器错误

Question

I have a main website xyz.org written in cake php which has below .htaccess rules. When I try to access the sub-domain it gives "500 Internal server errors" even if I had placed only index.php at sub domain directory.

Below is the .htaccess of the root

<IfModule mod_rewrite.c>
 RewriteEngine On
 RewriteRule    ^$ app/webroot/    [L]
 RewriteRule    (.*) app/webroot/$1 [L]
</IfModule>

<IfModule mod_php5.c>
 php_value max_execution_time 259200
</IfModule>

I have main domain website in cakephp framework and sub domain in yii.