WHMCS Integration stop on Configuration Step

I've setup WHMCS Provisioning and WHMCS WP Integration on same host with my WHMCS installation. My WHMCS installation is at http://client.pixnesia.com but when i integrated it to http://mytokoonline.com/client and try to made an order, it stop on configuration step (after select domain). But it's ok when i try it direct on whmcs installation.